#!/usr/bin/env python3
"""
Axes filled with cartographic projections.
"""
from __future__ import annotations
import copy
import inspect
from functools import partial
try:
# From python 3.12
from typing import override
except ImportError:
# From Python 3.5
from typing_extensions import override
from collections.abc import Iterator, Mapping, MutableMapping, Sequence
from typing import Any, Optional, Protocol
import matplotlib.axis as maxis
import matplotlib.collections as mcollections
import matplotlib.patches as mpatches
import matplotlib.path as mpath
import matplotlib.text as mtext
import matplotlib.ticker as mticker
import matplotlib.transforms as mtransforms
import numpy as np
from .. import constructor
from .. import proj as pproj
from .. import ticker as pticker
from ..config import rc
from ..internals import (
_not_none,
_pop_params,
_pop_props,
_pop_rc,
_version_cartopy,
docstring,
ic, # noqa: F401
labels,
warnings,
)
from ..utils import units
from . import plot, shared
try:
import cartopy.crs as ccrs
import cartopy.feature as cfeature
import cartopy.mpl.gridliner as cgridliner
from cartopy.crs import Projection
from cartopy.mpl.geoaxes import GeoAxes as _GeoAxes
except ModuleNotFoundError:
ccrs = cfeature = cgridliner = None
_GeoAxes = Projection = object
try:
from mpl_toolkits.basemap import Basemap
except ModuleNotFoundError:
Basemap = object
__all__ = ["GeoAxes"]
# Basemap gridlines are dicts keyed by location containing (lines, labels).
GridlineDict = MutableMapping[float, tuple[list[Any], list[mtext.Text]]]
_GRIDLINER_PAD_SCALE = 2.0 # points; matches tick size visually
_MINOR_TICK_SCALE = 0.6 # relative to major tick length
_BASEMAP_LABEL_SIZE_SCALE = 0.5 # empirical scaling for label offset
_BASEMAP_LABEL_Y_SCALE = 0.65 # empirical spacing to mimic cartopy
_BASEMAP_LABEL_X_SCALE = 0.25 # empirical spacing to mimic cartopy
_CARTOPY_LABEL_SIDES = ("labelleft", "labelright", "labelbottom", "labeltop", "geo")
_BASEMAP_LABEL_SIDES = ("labelleft", "labelright", "labelbottom", "labeltop", "geo")
# Format docstring
_format_docstring = """
round : bool, default: :rc:`geo.round`
*For polar cartopy axes only*.
Whether to bound polar projections with circles rather than squares. Note that outer
gridline labels cannot be added to circle-bounded polar projections. When basemap
is the backend this argument must be passed to `~ultraplot.constructor.Proj` instead.
extent : {'globe', 'auto'}, default: :rc:`geo.extent`
*For cartopy axes only*.
Whether to auto adjust the map bounds based on plotted content. If ``'globe'`` then
non-polar projections are fixed with `~cartopy.mpl.geoaxes.GeoAxes.set_global`,
non-Gnomonic polar projections are bounded at the equator, and Gnomonic polar
projections are bounded at 30 degrees latitude. If ``'auto'`` nothing is done.
lonlim, latlim : 2-tuple of float, optional
*For cartopy axes only.*
The approximate longitude and latitude boundaries of the map, applied
with `~cartopy.mpl.geoaxes.GeoAxes.set_extent`. When basemap is the backend
this argument must be passed to `~ultraplot.constructor.Proj` instead.
boundinglat : float, optional
*For cartopy axes only.*
The edge latitude for the circle bounding North Pole and South Pole-centered
projections. When basemap is the backend this argument must be passed to
`~ultraplot.constructor.Proj` instead.
longrid, latgrid, grid : bool, default: :rc:`grid`
Whether to draw longitude and latitude gridlines.
Use the keyword `grid` to toggle both at once.
longridminor, latgridminor, gridminor : bool, default: :rc:`gridminor`
Whether to draw "minor" longitude and latitude lines.
Use the keyword `gridminor` to toggle both at once.
lonticklen, latticklen, ticklen : unit-spec, default: :rc:`tick.len`
Major tick lengths for the longitudinal (x) and latitude (y) axis.
%(units.pt)s
Use the keyword `ticklen` to set both at once.
latmax : float, default: 80
The maximum absolute latitude for gridlines. Longitude gridlines are cut off
poleward of this value (note this feature does not work in cartopy 0.18).
nsteps : int, default: :rc:`grid.nsteps`
*For cartopy axes only.*
The number of interpolation steps used to draw gridlines.
lonlines, latlines : optional
Aliases for `lonlocator`, `latlocator`.
lonlocator, latlocator : locator-spec, optional
Used to determine the longitude and latitude gridline locations.
Passed to the `~ultraplot.constructor.Locator` constructor. Can be
string, float, list of float, or `matplotlib.ticker.Locator` instance.
For basemap or cartopy < 0.18, the defaults are ``'deglon'`` and
``'deglat'``, which correspond to the `~ultraplot.ticker.LongitudeLocator`
and `~ultraplot.ticker.LatitudeLocator` locators (adapted from cartopy).
For cartopy >= 0.18, the defaults are ``'dmslon'`` and ``'dmslat'``,
which uses the same locators with ``dms=True``. This selects gridlines
at nice degree-minute-second intervals when the map extent is very small.
lonlines_kw, latlines_kw : optional
Aliases for `lonlocator_kw`, `latlocator_kw`.
lonlocator_kw, latlocator_kw : dict-like, optional
Keyword arguments passed to the `matplotlib.ticker.Locator` class.
lonminorlocator, latminorlocator, lonminorlines, latminorlines : optional
As with `lonlocator` and `latlocator` but for the "minor" gridlines.
lonminorlines_kw, latminorlines_kw : optional
Aliases for `lonminorlocator_kw`, `latminorlocator_kw`.
lonminorlocator_kw, latminorlocator_kw : optional
As with `lonlocator_kw`, and `latlocator_kw` but for the "minor" gridlines.
lonlabels, latlabels, labels : str, bool, or sequence, :rc:`grid.labels`
Whether to add non-inline longitude and latitude gridline labels, and on
which sides of the map. Use the keyword `labels` to set both at once. The
argument must conform to one of the following options:
* A boolean. ``True`` indicates the bottom side for longitudes and
the left side for latitudes, and ``False`` disables all labels.
* A string or sequence of strings indicating the side names, e.g.
``'top'`` for longitudes or ``('left', 'right')`` for latitudes.
* A string indicating the side names with single characters, e.g.
``'bt'`` for longitudes or ``'lr'`` for latitudes.
* A string matching ``'neither'`` (no labels), ``'both'`` (equivalent
to ``'bt'`` for longitudes and ``'lr'`` for latitudes), or ``'all'``
(equivalent to ``'lrbt'``, i.e. all sides).
* A boolean 2-tuple indicating whether to draw labels
on the ``(bottom, top)`` sides for longitudes,
and the ``(left, right)`` sides for latitudes.
* A boolean 4-tuple indicating whether to draw labels on the
``(left, right, bottom, top)`` sides, as with the basemap
:func:`~mpl_toolkits.basemap.Basemap.drawmeridians` and
:func:`~mpl_toolkits.basemap.Basemap.drawparallels` `labels` keyword.
loninline, latinline, inlinelabels : bool, default: :rc:`grid.inlinelabels`
*For cartopy axes only.*
Whether to add inline longitude and latitude gridline labels. Use
the keyword `inlinelabels` to set both at once.
rotatelabels : bool, default: :rc:`grid.rotatelabels`
*For cartopy axes only.*
Whether to rotate non-inline gridline labels so that they automatically
follow the map boundary curvature.
labelrotation : float, optional
The rotation angle in degrees for both longitude and latitude tick labels.
Use `lonlabelrotation` and `latlabelrotation` to set them separately.
lonlabelrotation : float, optional
The rotation angle in degrees for longitude tick labels.
Works for both cartopy and basemap backends.
latlabelrotation : float, optional
The rotation angle in degrees for latitude tick labels.
Works for both cartopy and basemap backends.
labelpad : unit-spec, default: :rc:`grid.labelpad`
*For cartopy axes only.*
The padding between non-inline gridline labels and the map boundary.
%(units.pt)s
dms : bool, default: :rc:`grid.dmslabels`
*For cartopy axes only.*
Whether the default locators and formatters should use "minutes" and "seconds"
for gridline labels on small scales rather than decimal degrees. Setting this to
``False`` is equivalent to ``ax.format(lonlocator='deglon', latlocator='deglat')``
and ``ax.format(lonformatter='deglon', latformatter='deglat')``.
lonformatter, latformatter : formatter-spec, optional
Formatter used to style longitude and latitude gridline labels.
Passed to the `~ultraplot.constructor.Formatter` constructor. Can be
string, list of string, or `matplotlib.ticker.Formatter` instance.
For basemap or cartopy < 0.18, the defaults are ``'deglon'`` and
``'deglat'``, which correspond to `~ultraplot.ticker.SimpleFormatter`
presets with degree symbols and cardinal direction suffixes.
For cartopy >= 0.18, the defaults are ``'dmslon'`` and ``'dmslat'``,
which uses cartopy's `~cartopy.mpl.ticker.LongitudeFormatter` and
`~cartopy.mpl.ticker.LatitudeFormatter` formatters with ``dms=True``.
This formats gridlines that do not fall on whole degrees as "minutes" and
"seconds" rather than decimal degrees. Use ``dms=False`` to disable this.
lonformatter_kw, latformatter_kw : dict-like, optional
Keyword arguments passed to the `matplotlib.ticker.Formatter` class.
land, ocean, coast, rivers, lakes, borders, innerborders : bool, optional
Toggles various geographic features. These are actually the
:rcraw:`land`, :rcraw:`ocean`, :rcraw:`coast`, :rcraw:`rivers`,
:rcraw:`lakes`, :rcraw:`borders`, and :rcraw:`innerborders`
settings passed to `~ultraplot.config.Configurator.context`.
The style can be modified using additional `rc` settings.
For example, to change :rcraw:`land.color`, use
``ax.format(landcolor='green')``, and to change
:rcraw:`land.zorder`, use ``ax.format(landzorder=4)``.
reso : {'lo', 'med', 'hi', 'x-hi', 'xx-hi'}, optional
*For cartopy axes only.*
The resolution of geographic features. When basemap is the backend this
must be passed to `~ultraplot.constructor.Proj` instead.
color : color-spec, default: :rc:`meta.color`
The color for the axes edge. Propagates to `labelcolor` unless specified
otherwise (similar to :func:`~ultraplot.axes.CartesianAxes.format`).
gridcolor : color-spec, default: :rc:`grid.color`
The color for the gridline labels.
labelcolor : color-spec, default: `color` or :rc:`grid.labelcolor`
The color for the gridline labels (`gridlabelcolor` is also allowed).
labelsize : unit-spec or str, default: :rc:`grid.labelsize`
The font size for the gridline labels (`gridlabelsize` is also allowed).
%(units.pt)s
labelweight : str, default: :rc:`grid.labelweight`
The font weight for the gridline labels (`gridlabelweight` is also allowed).
"""
docstring._snippet_manager["geo.format"] = _format_docstring
_choropleth_docstring = """
Draw polygon geometries colored by numeric values.
Parameters
----------
geometries
Sequence of polygon-like shapely geometries. Typical inputs include
GeoPandas ``geometry`` arrays or lists of shapely polygons in
longitude-latitude coordinates. When `country=True`, this can also
be a sequence of country codes/names or a mapping of country
identifiers to values.
values
Numeric values mapped to colors. Must have the same length as
`geometries`. Optional when `country=True` and `geometries` is a
mapping of country identifiers to values.
transform : cartopy CRS, optional
The input coordinate system for `geometries`. By default, cartopy
backends assume `~cartopy.crs.PlateCarree` and basemap backends
assume longitude-latitude input.
country : bool, optional
Interpret `geometries` as country identifiers and resolve them to
Natural Earth polygons before plotting.
country_reso : {'110m', '50m', '10m'}, optional
The Natural Earth country resolution used when `country=True`.
Defaults to :rc:`geo.choropleth.country_reso`.
country_territories : bool, optional
Whether to keep distant territories for multi-part country
geometries when `country=True`. Defaults to
:rc:`geo.choropleth.country_territories`.
colorbar, colorbar_kw
Passed to `~ultraplot.axes.Axes.colorbar`.
missing_kw : dict-like, optional
Style applied to geometries whose values are missing or non-finite.
If omitted, missing geometries are skipped.
Other parameters
----------------
cmap, cmap_kw, norm, norm_kw, vmin, vmax, levels, values
Standard UltraPlot colormap arguments.
edgecolor, linewidth, alpha, hatch, rasterized, zorder, label, ...
Collection styling arguments passed to the polygon collection.
Returns
-------
matplotlib.collections.PatchCollection
The scalar-mappable collection for finite-valued polygons.
"""
docstring._snippet_manager["geo.choropleth"] = _choropleth_docstring
class _GeoLabel(object):
"""
Optionally omit overlapping check if an rc setting is disabled.
"""
def check_overlapping(self, *args: Any, **kwargs: Any) -> bool:
if rc["grid.checkoverlap"]:
return super().check_overlapping(*args, **kwargs)
else:
return False
if cgridliner is not None and hasattr(cgridliner, "Label"): # only recent versions
class _CartopyLabel(_GeoLabel, cgridliner.Label):
"""Label class with configurable overlap checks."""
class _CartopyGridliner(cgridliner.Gridliner):
"""
Gridliner subclass to localize cartopy quirks in one place.
"""
LabelClass = _CartopyLabel
def _generate_labels(self) -> Iterator[_CartopyLabel]:
"""Yield label objects, reusing cached instances when possible."""
for label in self._all_labels:
yield label
while True:
new_artist = mtext.Text()
new_artist.set_figure(self.axes.figure)
new_artist.axes = self.axes
new_label = self.LabelClass(new_artist, None, None, None)
self._all_labels.append(new_label)
yield new_label
def _axes_domain(self, *args: Any, **kwargs: Any) -> tuple[Any, Any]:
x_range, y_range = super()._axes_domain(*args, **kwargs)
if _version_cartopy < "0.18":
lon_0 = self.axes.projection.proj4_params.get("lon_0", 0)
x_range = np.asarray(x_range) + lon_0
return x_range, y_range
def _draw_gridliner(self, *args: Any, **kwargs: Any) -> Any: # noqa: E306
result = super()._draw_gridliner(*args, **kwargs)
if _version_cartopy >= "0.18":
lon_lim, _ = self._axes_domain()
if abs(np.diff(lon_lim)) == abs(np.diff(self.crs.x_limits)):
for collection in self.xline_artists:
if not getattr(collection, "_cartopy_fix", False):
collection.get_paths().pop(-1)
collection._cartopy_fix = True
return result
else:
_CartopyGridliner = None
class _GeoAxis(object):
"""
Dummy axis used by longitude and latitude locators and for storing view limits on
longitude and latitude coordinates. Modeled after how `matplotlib.ticker._DummyAxis`
and `matplotlib.ticker.TickHelper` are used to control tick locations and labels.
"""
# NOTE: Due to cartopy bug (https://github.com/SciTools/cartopy/issues/1564)
# we store presistent longitude and latitude locators on axes, then *call*
# them whenever set_extent is called and apply *fixed* locators.
def __init__(self, axes: "GeoAxes") -> None:
self.axes = axes
self.major = maxis.Ticker()
self.minor = maxis.Ticker()
self.isDefault_majfmt = True
self.isDefault_majloc = True
self.isDefault_minloc = True
self._interval = None
self._use_dms = (
ccrs is not None
and isinstance(
axes.projection, (ccrs._RectangularProjection, ccrs.Mercator)
) # noqa: E501
and _version_cartopy >= "0.18"
)
def _get_extent(self) -> tuple[float, float, float, float]:
# Try to get extent but bail out for projections where this is
# impossible. So far just transverse Mercator
try:
return self.axes.get_extent()
except Exception:
lon0 = self.axes._get_lon0()
return (-180 + lon0, 180 + lon0, -90, 90)
@staticmethod
def _pad_ticks(ticks: np.ndarray, vmin: float, vmax: float) -> np.ndarray:
# Wrap up to the longitude/latitude range to avoid
# giant lists of 10,000 gridline locations.
if len(ticks) == 0:
return ticks
range_ = np.max(ticks) - np.min(ticks)
vmin = max(vmin, ticks[0] - range_)
vmax = min(vmax, ticks[-1] + range_)
# Pad the reported tick range up to specified range
step = ticks[1] - ticks[0] # MaxNLocator/AutoMinorLocator steps are equal
ticks_lo = np.arange(ticks[0], vmin, -step)[1:][::-1]
ticks_hi = np.arange(ticks[-1], vmax, step)[1:]
ticks = np.concatenate((ticks_lo, ticks, ticks_hi))
return ticks
def get_scale(self) -> str:
return "linear"
def get_tick_space(self) -> int:
return 9 # longstanding default of nbins=9
def get_major_formatter(self) -> mticker.Formatter | None:
return self.major.formatter
def get_major_locator(self) -> mticker.Locator | None:
return self.major.locator
def get_minor_locator(self) -> mticker.Locator | None:
return self.minor.locator
def get_majorticklocs(self) -> np.ndarray:
return self._get_ticklocs(self.major.locator)
def get_minorticklocs(self) -> np.ndarray:
return self._get_ticklocs(self.minor.locator)
def set_major_formatter(
self, formatter: mticker.Formatter, default: bool = False
) -> None:
# NOTE: Cartopy formatters check Formatter.axis.axes.projection
# in order to implement special projection-dependent behavior.
self.major.formatter = formatter
formatter.set_axis(self)
self.isDefault_majfmt = default
def set_major_locator(
self, locator: mticker.Locator, default: bool = False
) -> None:
self.major.locator = locator
if self.major.formatter:
self.major.formatter._set_locator(locator)
locator.set_axis(self)
self.isDefault_majloc = default
def set_minor_locator(
self, locator: mticker.Locator, default: bool = False
) -> None:
self.minor.locator = locator
locator.set_axis(self)
self.isDefault_majfmt = default
def set_view_interval(self, vmin: float, vmax: float) -> None:
self._interval = (vmin, vmax)
def _copy_locator_properties(self, other: "_GeoAxis") -> None:
"""
This function copies the locator properties. It is
used when the @self is sharing with @other.
"""
props = [
"isDefault_majloc",
"isDefault_minloc",
"isDefault_majfmt",
]
funcs = [
"major_locator",
"minor_locator",
"major_formatter",
]
for prop, func in zip(props, funcs):
# Copy if props differ from this to other
this_prop = getattr(self, prop)
other_prop = getattr(other, prop)
if this_prop ^ other_prop:
# Allow this to error if in the unlikely
# case that the backend changes
getter = getattr(self, f"get_{func}")
setter = getattr(other, f"set_{func}")
setter(getter())
setattr(other, prop, this_prop)
class _GridlinerAdapter(Protocol):
"""
Lightweight facade used to normalize cartopy and basemap gridliner behavior.
These adapters let GeoAxes apply gridline label toggles and styles without
backend-specific branching.
"""
def labels_for_sides(
self,
*,
bottom: bool | str | None = None,
top: bool | str | None = None,
left: bool | str | None = None,
right: bool | str | None = None,
) -> dict[str, list[mtext.Text]]: ...
def toggle_labels(
self,
*,
labelleft: bool | str | None = None,
labelright: bool | str | None = None,
labelbottom: bool | str | None = None,
labeltop: bool | str | None = None,
geo: bool | str | None = None,
) -> None: ...
def apply_style(
self,
*,
axis: str = "both",
pad: float | None = None,
labelsize: float | str | None = None,
labelcolor: Any = None,
labelrotation: float | None = None,
linecolor: Any = None,
linewidth: float | None = None,
) -> None: ...
def tick_positions(
self, axis: str, *, lonaxis: "_GeoAxis", lataxis: "_GeoAxis"
) -> np.ndarray: ...
def is_label_on(self, side: str) -> bool: ...
class _CartopyGridlinerProtocol(Protocol):
"""
Structural protocol for the subset of cartopy Gridliner attributes we use.
This keeps type hints tight without importing cartopy at runtime.
"""
collection_kwargs: dict[str, Any]
xlabel_style: dict[str, Any]
ylabel_style: dict[str, Any]
xlocator: mticker.Locator
ylocator: mticker.Locator
xpadding: float | None
ypadding: float | None
xlines: bool
ylines: bool
x_inline: bool | None
y_inline: bool | None
rotate_labels: bool | None
inline_labels: bool | str | None
geo_labels: bool | str | None
left_label_artists: list[mtext.Text]
right_label_artists: list[mtext.Text]
bottom_label_artists: list[mtext.Text]
top_label_artists: list[mtext.Text]
xline_artists: list[Any]
def _axes_domain(self, *args: Any, **kwargs: Any) -> tuple[Any, Any]: ...
def _draw_gridliner(self, *args: Any, **kwargs: Any) -> Any: ...
class _CartopyGridlinerAdapter(_GridlinerAdapter):
"""
Adapter for cartopy's Gridliner, translating common label/style operations
into the Gridliner API while hiding cartopy version differences.
"""
def __init__(self, gridliner: Optional[_CartopyGridlinerProtocol]) -> None:
self.gridliner = gridliner
@staticmethod
def _side_labels() -> tuple[str, str, str, str]:
# Cartopy label attribute names vary by version.
if _version_cartopy >= "0.18":
left_labels = "left_labels"
right_labels = "right_labels"
bottom_labels = "bottom_labels"
top_labels = "top_labels"
else: # cartopy < 0.18
left_labels = "ylabels_left"
right_labels = "ylabels_right"
bottom_labels = "xlabels_bottom"
top_labels = "xlabels_top"
return (left_labels, right_labels, bottom_labels, top_labels)
def labels_for_sides(
self,
*,
bottom: bool | str | None = None,
top: bool | str | None = None,
left: bool | str | None = None,
right: bool | str | None = None,
) -> dict[str, list[mtext.Text]]:
sides = {}
gl = self.gridliner
if gl is None:
return sides
for dir, side in zip(
"bottom top left right".split(), [bottom, top, left, right]
):
if side != True:
continue
sides[dir] = getattr(gl, f"{dir}_label_artists")
return sides
def toggle_labels(
self,
*,
labelleft: bool | str | None = None,
labelright: bool | str | None = None,
labelbottom: bool | str | None = None,
labeltop: bool | str | None = None,
geo: bool | str | None = None,
) -> None:
gl = self.gridliner
if gl is None:
return
side_labels = self._side_labels()
togglers = (labelleft, labelright, labelbottom, labeltop)
for toggle, side in zip(togglers, side_labels):
if toggle is not None:
setattr(gl, side, toggle)
if geo is not None: # only cartopy 0.20 supported but harmless
setattr(gl, "geo_labels", geo)
def apply_style(
self,
*,
axis: str = "both",
pad: float | None = None,
labelsize: float | str | None = None,
labelcolor: Any = None,
labelrotation: float | None = None,
linecolor: Any = None,
linewidth: float | None = None,
) -> None:
gl = self.gridliner
if gl is None:
return
def _apply_label_style(style: dict[str, Any]) -> None:
if labelcolor is not None:
style["color"] = labelcolor
if labelsize is not None:
style["fontsize"] = labelsize
if labelrotation is not None:
style["rotation"] = labelrotation
# Cartopy line styling is stored in the collection kwargs.
if linecolor is not None:
gl.collection_kwargs["color"] = linecolor
if linewidth is not None:
gl.collection_kwargs["linewidth"] = linewidth
if axis in ("x", "both"):
_apply_label_style(gl.xlabel_style)
if pad is not None and hasattr(gl, "xpadding"):
gl.xpadding = pad
if axis in ("y", "both"):
_apply_label_style(gl.ylabel_style)
if pad is not None and hasattr(gl, "ypadding"):
gl.ypadding = pad
def tick_positions(
self, axis: str, *, lonaxis: _GeoAxis, lataxis: _GeoAxis
) -> np.ndarray:
gl = self.gridliner
if gl is None:
return np.asarray([])
if axis == "x":
locator = gl.xlocator
if locator is None:
return np.asarray([])
return lonaxis._get_ticklocs(locator)
if axis == "y":
locator = gl.ylocator
if locator is None:
return np.asarray([])
return lataxis._get_ticklocs(locator)
raise ValueError(f"Invalid axis: {axis!r}")
def is_label_on(self, side: str) -> bool:
gl = self.gridliner
if gl is None:
return False
left_labels, right_labels, bottom_labels, top_labels = self._side_labels()
if side == "labelleft":
return getattr(gl, left_labels)
elif side == "labelright":
return getattr(gl, right_labels)
elif side == "labelbottom":
return getattr(gl, bottom_labels)
elif side == "labeltop":
return getattr(gl, top_labels)
else:
raise ValueError(f"Invalid side: {side}")
class _BasemapGridlinerAdapter(_GridlinerAdapter):
"""
Adapter for basemap meridian/parallel dictionaries, emulating the subset
of cartopy Gridliner behavior needed by GeoAxes (labels, toggles, styling).
"""
def __init__(
self,
lonlines: GridlineDict | None,
latlines: GridlineDict | None,
) -> None:
self.lonlines = lonlines
self.latlines = latlines
def labels_for_sides(
self,
*,
bottom: bool | str | None = None,
top: bool | str | None = None,
left: bool | str | None = None,
right: bool | str | None = None,
) -> dict[str, list[mtext.Text]]:
directions = "left right top bottom".split()
bools = [left, right, top, bottom]
sides = {}
for direction, is_on in zip(directions, bools):
if is_on is None:
continue
gl = self.lonlines
if direction in ["left", "right"]:
gl = self.latlines
for loc, (lines, labels) in (gl or {}).items():
for label in labels:
# Determine side by label position (Basemap clusters by location).
position = label.get_position()
match direction:
case "top" if position[1] > 0:
add = True
case "bottom" if position[1] < 0:
add = True
case "left" if position[0] < 0:
add = True
case "right" if position[0] > 0:
add = True
case _:
add = False
if add:
sides.setdefault(direction, []).append(label)
return sides
def toggle_labels(
self,
*,
labelleft: bool | str | None = None,
labelright: bool | str | None = None,
labelbottom: bool | str | None = None,
labeltop: bool | str | None = None,
geo: bool | str | None = None,
) -> None:
labels = self.labels_for_sides(
bottom=labelbottom, top=labeltop, left=labelleft, right=labelright
)
toggles = {
"bottom": labelbottom,
"top": labeltop,
"left": labelleft,
"right": labelright,
}
for direction, toggle in toggles.items():
if toggle is None:
continue
for label in labels.get(direction, []):
label.set_visible(bool(toggle) or toggle in ("x", "y"))
def apply_style(
self,
*,
axis: str = "both",
pad: float | None = None,
labelsize: float | str | None = None,
labelcolor: Any = None,
labelrotation: float | None = None,
linecolor: Any = None,
linewidth: float | None = None,
) -> None:
pad # unused for basemap gridlines
targets = []
if axis in ("x", "both"):
targets.append(self.lonlines)
if axis in ("y", "both"):
targets.append(self.latlines)
for gl in targets:
for loc, (lines, labels) in (gl or {}).items():
# Basemap stores line artists and label text separately.
for line in lines:
if linecolor is not None and hasattr(line, "set_color"):
line.set_color(linecolor)
if linewidth is not None and hasattr(line, "set_linewidth"):
line.set_linewidth(linewidth)
for label in labels:
if labelcolor is not None:
label.set_color(labelcolor)
if labelsize is not None:
label.set_fontsize(labelsize)
if labelrotation is not None:
label.set_rotation(labelrotation)
def tick_positions(
self, axis: str, *, lonaxis: _GeoAxis, lataxis: _GeoAxis
) -> np.ndarray:
lonaxis, lataxis # unused; tick positions are stored in dict keys
if axis == "x":
locator = self.lonlines
elif axis == "y":
locator = self.latlines
else:
raise ValueError(f"Invalid axis: {axis!r}")
if not locator:
return np.asarray([])
return np.asarray(list(locator.keys()))
def is_label_on(self, side: str) -> bool:
def group_labels(
labels: list[mtext.Text],
which: str,
labelbottom: bool | str | None = None,
labeltop: bool | str | None = None,
labelleft: bool | str | None = None,
labelright: bool | str | None = None,
) -> dict[str, list[mtext.Text]]:
group = {}
for label in labels:
position = label.get_position()
target = None
if which == "x":
if labelbottom is not None and position[1] < 0:
target = "labelbottom"
elif labeltop is not None and position[1] >= 0:
target = "labeltop"
else:
if labelleft is not None and position[0] < 0:
target = "labelleft"
elif labelright is not None and position[0] >= 0:
target = "labelright"
if target is not None:
group[target] = group.get(target, []) + [label]
return group
gl = self.lonlines
which = "x"
if side in ["labelleft", "labelright"]:
gl = self.latlines
which = "y"
for loc, (line, labels) in (gl or {}).items():
grouped = group_labels(
labels=labels,
which=which,
**{side: True},
)
for label in grouped.get(side, []):
if label.get_visible():
return True
return False
class _LonAxis(_GeoAxis):
"""
Axis with default longitude locator.
"""
axis_name = "lon"
# NOTE: Basemap accepts tick formatters with drawmeridians(fmt=Formatter())
# Try to use cartopy formatter if cartopy installed. Otherwise use
# default builtin basemap formatting.
def __init__(self, axes: "GeoAxes") -> None:
super().__init__(axes)
if self._use_dms:
locator = formatter = "dmslon"
else:
locator = formatter = "deglon"
self.set_major_formatter(
constructor.Formatter(formatter),
default=True,
)
self.set_major_locator(constructor.Locator(locator), default=True)
self.set_minor_locator(mticker.AutoMinorLocator(), default=True)
def _get_ticklocs(self, locator: mticker.Locator) -> np.ndarray:
# Prevent ticks from looping around
# NOTE: Cartopy 0.17 formats numbers offset by eps with the cardinal indicator
# (e.g. 0 degrees for map centered on 180 degrees). So skip in that case.
# NOTE: Common strange issue is e.g. MultipleLocator(60) starts out at
# -60 degrees for a map from 0 to 360 degrees. If always trimmed circular
# locations from right then would cut off rightmost gridline. Workaround is
# to trim on the side closest to central longitude (in this case the left).
eps = 1e-10
# We set lon0 in the Formatter here
# as initially the formatter is parsed
# as a SimpleFormatter. Here, the formatter
# should be a LongitudinalFormatter.
lon0 = self.axes._get_lon0()
formatter = self.get_major_formatter()
formatter.lon0 = lon0 # update if necessary
ticks = np.sort(locator())
while ticks.size:
if np.isclose(ticks[0] + 360, ticks[-1]):
if _version_cartopy >= "0.18" or not np.isclose(ticks[0] % 360, 0):
ticks[-1] -= eps # ensure label appears on *right* not left
break
elif ticks[0] + 360 < ticks[-1]:
idx = (1, None) if lon0 - ticks[0] > ticks[-1] - lon0 else (None, -1)
ticks = ticks[slice(*idx)] # cut off ticks looped over globe
else:
break
# Append extra ticks in case longitude/latitude limits do not encompass
# the entire view range of map, e.g. for Lambert Conformal sectors.
# NOTE: Try to avoid making 10,000 element lists. Just wrap extra ticks
# up to the width of *reported* longitude range.
if isinstance(locator, (mticker.MaxNLocator, mticker.AutoMinorLocator)):
ticks = self._pad_ticks(ticks, lon0 - 180 + eps, lon0 + 180 - eps)
return ticks
def get_view_interval(self) -> tuple[float, float]:
# NOTE: ultraplot tries to set its *own* view intervals to avoid dateline
# weirdness, but if rc['geo.extent'] is 'auto' the interval will be unset.
# In this case we use _get_extent() as a backup.
interval = self._interval
if interval is None:
extent = self._get_extent()
interval = extent[:2] # longitude extents
return interval
class _LatAxis(_GeoAxis):
"""
Axis with default latitude locator.
"""
axis_name = "lat"
def __init__(self, axes: "GeoAxes", latmax: float = 90) -> None:
# NOTE: Need to pass projection because lataxis/lonaxis are
# initialized before geoaxes is initialized, because format() needs
# the axes and format() is called by ultraplot.axes.Axes.__init__()
self._latmax = latmax
super().__init__(axes)
if self._use_dms:
locator = formatter = "dmslat"
else:
locator = formatter = "deglat"
self.set_major_formatter(constructor.Formatter(formatter), default=True)
self.set_major_locator(constructor.Locator(locator), default=True)
self.set_minor_locator(mticker.AutoMinorLocator(), default=True)
def _get_ticklocs(self, locator: mticker.Locator) -> np.ndarray:
# Adjust latitude ticks to fix bug in some projections. Harmless for basemap.
# NOTE: Maybe this was fixed by cartopy 0.18?
eps = 1e-10
ticks = np.sort(locator())
if ticks.size:
if ticks[0] == -90:
ticks[0] += eps
if ticks[-1] == 90:
ticks[-1] -= eps
# Append extra ticks in case longitude/latitude limits do not encompass
# the entire view range of map, e.g. for Lambert Conformal sectors.
if isinstance(locator, (mticker.MaxNLocator, mticker.AutoMinorLocator)):
ticks = self._pad_ticks(ticks, -90 + eps, 90 - eps)
# Filter ticks to latmax range
latmax = self.get_latmax()
ticks = ticks[(ticks >= -latmax) & (ticks <= latmax)]
return ticks
def get_latmax(self) -> float:
return self._latmax
def get_view_interval(self) -> tuple[float, float]:
interval = self._interval
if interval is None:
extent = self._get_extent()
interval = extent[2:] # latitudes
return interval
def set_latmax(self, latmax: float) -> None:
self._latmax = latmax
def _gridliner_sides_from_arrays(
lonarray: Sequence[bool | None] | None,
latarray: Sequence[bool | None] | None,
*,
order: Sequence[str],
allow_xy: bool,
include_false: bool,
) -> dict[str, bool | str]:
"""
Map lon/lat label arrays to gridliner toggle flags.
Parameters
----------
allow_xy
Use "x"/"y" to preserve axis-specific toggles when only one of lon/lat
is enabled for a given side (cartopy behavior).
include_false
Include explicit False entries to actively hide existing labels instead
of leaving previous state untouched (backend-dependent behavior).
"""
if lonarray is None or latarray is None:
return {}
sides: dict[str, bool | str] = {}
for side, lon, lat in zip(order, lonarray, latarray):
value: bool | str | None = None
if allow_xy:
if lon and lat:
value = True
elif lon:
value = "x"
elif lat:
value = "y"
elif include_false and (lon is not None or lat is not None):
value = False
else:
if lon or lat:
value = True
elif include_false and (lon is not None or lat is not None):
value = False
if value is not None:
sides[side] = value
return sides
[docs]
class GeoAxes(shared._SharedAxes, plot.PlotAxes):
"""
Axes subclass for plotting in geographic projections. Uses either cartopy
or basemap as a "backend".
Note
----
This subclass uses longitude and latitude as the default coordinate system for all
plotting commands by internally passing ``transform=cartopy.crs.PlateCarree()`` to
cartopy commands and ``latlon=True`` to basemap commands. Also, when using basemap
as the "backend", plotting is still done "cartopy-style" by calling methods from
the axes instance rather than the `~mpl_toolkits.basemap.Basemap` instance.
Important
---------
This axes subclass can be used by passing ``proj='proj_name'``
to axes-creation commands like `~ultraplot.figure.Figure.add_axes`,
`~ultraplot.figure.Figure.add_subplot`, and `~ultraplot.figure.Figure.subplots`,
where ``proj_name`` is a registered :ref:`PROJ projection name <proj_table>`.
You can also pass a `~cartopy.crs.Projection` or `~mpl_toolkits.basemap.Basemap`
instance instead of a projection name. Alternatively, you can pass any of the
matplotlib-recognized axes subclass names ``proj='cartopy'``, ``proj='geo'``, or
``proj='geographic'`` with a `~cartopy.crs.Projection` `map_projection` keyword
argument, or pass ``proj='basemap'`` with a `~mpl_toolkits.basemap.Basemap`
`map_projection` keyword argument.
"""
@docstring._snippet_manager
def __init__(self, *args: Any, **kwargs: Any) -> None:
"""
Parameters
----------
*args
Passed to `matplotlib.axes.Axes`.
map_projection : `~cartopy.crs.Projection` or `~mpl_toolkits.basemap.Basemap`
The cartopy or basemap projection instance. This is
passed automatically when calling axes-creation
commands like `~ultraplot.figure.Figure.add_subplot`.
%(geo.format)s
Other parameters
----------------
%(axes.format)s
%(rc.init)s
See also
--------
GeoAxes.format
ultraplot.constructor.Proj
ultraplot.axes.Axes
ultraplot.axes.PlotAxes
ultraplot.figure.Figure.subplot
ultraplot.figure.Figure.add_subplot
"""
# Cache of backend-specific gridliner adapters (major/minor).
self._gridliner_adapters: dict[str, _GridlinerAdapter] = {}
# Extra cartopy edge labels (e.g., endpoint longitudes).
self._edge_lon_labels: list[mtext.Text] = []
self._edge_lat_labels: list[mtext.Text] = []
super().__init__(*args, **kwargs)
@override
def _sharey_limits(self, sharey: "GeoAxes") -> None:
return self._share_limits_with(sharey, which="y")
@override
def _sharex_limits(self, sharex: "GeoAxes") -> None:
return self._share_limits_with(sharex, which="x")
def _share_limits_with(self, other: "GeoAxes", which: str) -> None:
"""
Safely share limits and tickers without resetting things.
"""
# NOTE: See _sharex_limits for notes
if which == "x":
this_ax = self._lonaxis
other_ax = other._lonaxis
else:
this_ax = self._lataxis
other_ax = other._lataxis
for ax1, ax2 in ((other_ax, this_ax), (this_ax, other_ax)):
ax1.set_view_interval(*ax2.get_view_interval())
# Set the shared axis
getattr(self, f"share{which}")(other)
this_ax._copy_locator_properties(other_ax)
def _is_rectilinear(self) -> bool:
return _is_rectilinear_projection(self)
def __share_axis_setup(
self,
other: "GeoAxes",
*,
which: str,
labels: bool,
limits: bool,
) -> None:
level = getattr(self.figure, f"_share{which}")
if getattr(self, f"_panel_share{which}_group") and self._is_panel_group_member(
other
):
level = 3
if level not in range(5): # must be internal error
raise ValueError(f"Invalid sharing level sharex={level!r}.")
if other in (None, self) or not isinstance(other, GeoAxes):
return
# Share future axis label changes. Implemented in _apply_axis_sharing().
# Matplotlib only uses these attributes in __init__() and cla() to share
# tickers -- all other builtin sharing features derives from shared x axes
if level > 0 and labels:
setattr(self, f"_share{which}", other)
# Share future axis tickers, limits, and scales
# NOTE: Only difference between levels 2 and 3 is level 3 hides ticklabels
# labels. But this is done after the fact -- tickers are still shared.
if level > 1 and limits:
self._share_limits_with(other, which=which)
@override
def _sharey_setup(
self, sharey: "GeoAxes", *, labels: bool = True, limits: bool = True
) -> None:
"""
Configure shared axes accounting for panels. The input is the
'parent' axes, from which this one will draw its properties.
"""
super()._sharey_setup(sharey, labels=labels, limits=limits)
return self.__share_axis_setup(sharey, which="y", labels=labels, limits=limits)
@override
def _sharex_setup(
self, sharex: "GeoAxes", *, labels: bool = True, limits: bool = True
) -> None:
# Share panels across *different* subplots
super()._sharex_setup(sharex, labels=labels, limits=limits)
return self.__share_axis_setup(sharex, which="x", labels=labels, limits=limits)
def _toggle_ticks(self, label: Any, which: str) -> None:
"""
Toggle x/y tick positions from geo label specifications.
Accepts the same `labels` forms as format(), including booleans, strings,
and boolean/string sequences. Only sides relevant to the requested axis
are considered: bottom/top for ``which='x'`` and left/right for
``which='y'``.
"""
if label is None:
return
is_lon = which == "x"
try:
array = self._to_label_array(label, lon=is_lon)
except ValueError:
warnings._warn_ultraplot(
f"Not toggling label={label!r}. Input was not understood."
)
return
if is_lon:
side0, side1 = bool(array[2]), bool(array[3]) # bottom, top
axis = self.xaxis
name0, name1 = "bottom", "top"
else:
side0, side1 = bool(array[0]), bool(array[1]) # left, right
axis = self.yaxis
name0, name1 = "left", "right"
if side0 and side1:
axis.set_ticks_position("both")
elif side0:
axis.set_ticks_position(name0)
elif side1:
axis.set_ticks_position(name1)
def _set_gridliner_adapter(
self, which: str, adapter: Optional[_GridlinerAdapter]
) -> None:
if adapter is None:
self._gridliner_adapters.pop(which, None)
else:
self._gridliner_adapters[which] = adapter
def _get_gridliner_adapter(self, which: str) -> Optional[_GridlinerAdapter]:
return self._gridliner_adapters.get(which)
def _gridliner_adapter(
self, which: str, *, create: bool = True
) -> Optional[_GridlinerAdapter]:
"""
Return a cached gridliner adapter, optionally creating it via the backend
builder when missing.
"""
adapter = self._get_gridliner_adapter(which)
if adapter is None and create:
builder = getattr(self, "_build_gridliner_adapter", None)
if builder is not None:
adapter = builder(which)
self._set_gridliner_adapter(which, adapter)
return adapter
def _iter_gridliner_adapters(self, which: str) -> Iterator[_GridlinerAdapter]:
"""
Yield available gridliner adapters for the requested tick selection.
"""
if which in ("major", "both"):
adapter = self._gridliner_adapter("major")
if adapter is not None:
yield adapter
if which in ("minor", "both"):
adapter = self._gridliner_adapter("minor")
if adapter is not None:
yield adapter
def _gridliner_tick_positions(
self, axis: str, *, which: str = "major"
) -> np.ndarray:
"""
Return tick positions from the backend gridliner for a given axis.
"""
if axis not in ("x", "y"):
raise ValueError(f"Invalid axis: {axis!r}")
adapter = self._gridliner_adapter(which)
if adapter is None:
return np.asarray([])
return adapter.tick_positions(
axis, lonaxis=self._lonaxis, lataxis=self._lataxis
)
[docs]
@override
def tick_params(self, *args: Any, **kwargs: Any) -> Any:
"""
Apply tick parameters and mirror a subset of settings onto the backend
gridliner artists so gridline labels respond to common tick tweaks.
"""
result = super().tick_params(*args, **kwargs)
axis = kwargs.get("axis", "both")
which = kwargs.get("which", "major")
pad = kwargs.get("pad", None)
labelsize = kwargs.get("labelsize", None)
labelcolor = kwargs.get(
"labelcolor", kwargs.get("colors", kwargs.get("color", None))
)
labelrotation = kwargs.get("labelrotation", None)
linecolor = kwargs.get("colors", kwargs.get("color", None))
linewidth = kwargs.get("width", kwargs.get("linewidth", None))
adapters = tuple(self._iter_gridliner_adapters(which))
if not adapters:
return result
for adapter in adapters:
adapter.apply_style(
axis=axis,
pad=pad,
labelsize=labelsize,
labelcolor=labelcolor,
labelrotation=labelrotation,
linecolor=linecolor,
linewidth=linewidth,
)
# Toggle label visibility for major gridliners when requested.
if which in ("major", "both"):
adapter = self._gridliner_adapter("major")
toggles = {}
if axis in ("x", "both"):
for key in ("labelbottom", "labeltop"):
if key in kwargs:
toggles[key] = kwargs[key]
if axis in ("y", "both"):
for key in ("labelleft", "labelright"):
if key in kwargs:
toggles[key] = kwargs[key]
if toggles and adapter is not None:
adapter.toggle_labels(**toggles)
self.stale = True
return result
def _apply_axis_sharing(self) -> None:
"""
Enforce the "shared" axis labels and axis tick labels. If this is not
called at drawtime, "shared" labels can be inadvertantly turned off.
Notes:
- Critical to apply labels to *shared* axes attributes rather than testing
extents or we end up sharing labels with twin axes.
- Similar to how align_super_labels() calls apply_title_above(), this is called
inside align_axis_labels() so we align the correct text.
- The "panel sharing group" refers to axes and panels *above* the bottommost
or to the *right* of the leftmost panel. But the sharing level used for
the leftmost and bottommost is the *figure* sharing level.
"""
# Share axis labels
if self._sharex and self.figure._sharex >= 1:
if self.figure._is_share_label_group_member(self, "x"):
pass
elif self.figure._is_share_label_group_member(self._sharex, "x"):
self.xaxis.label.set_visible(False)
else:
labels._transfer_label(self.xaxis.label, self._sharex.xaxis.label)
self.xaxis.label.set_visible(False)
if self._sharey and self.figure._sharey >= 1:
if self.figure._is_share_label_group_member(self, "y"):
pass
elif self.figure._is_share_label_group_member(self._sharey, "y"):
self.yaxis.label.set_visible(False)
else:
labels._transfer_label(self.yaxis.label, self._sharey.yaxis.label)
self.yaxis.label.set_visible(False)
# Share interval x
if self._sharex and self.figure._sharex >= 2:
self._lonaxis.set_view_interval(*self._sharex._lonaxis.get_view_interval())
self._lonaxis.set_minor_locator(self._sharex._lonaxis.get_minor_locator())
# Share interval y
if self._sharey and self.figure._sharey >= 2:
self._lataxis.set_view_interval(*self._sharey._lataxis.get_view_interval())
self._lataxis.set_minor_locator(self._sharey._lataxis.get_minor_locator())
def _apply_aspect_and_adjust_panels(self, *, tol: float = 1e-9) -> None:
"""
Apply aspect and then align panels to the adjusted axes box.
Notes
-----
Cartopy and basemap use different tolerances when detecting whether
apply_aspect() actually changed the axes position.
"""
self.apply_aspect()
self._adjust_panel_positions(tol=tol)
def _compute_span_extent(self, side, panel, gs, p_r1, p_r2, p_c1, p_c2):
"""
If the panel spans beyond the parent's SubplotSpec, compute the visual
extent (min, max) along the span axis from all non-panel axes in range.
Returns None if not a span override or no valid extent found.
"""
# NOTE: This will move to a layout composer in a future refactor.
ss = getattr(panel, "get_subplotspec", lambda: None)()
if ss is None or p_c1 is None:
return None
panel_ss = ss.get_topmost_subplotspec()
s_r1, s_r2, s_c1, s_c2 = panel_ss._get_rows_columns(ncols=gs.ncols_total)
if side in ("bottom", "top"):
has_span_override = s_c1 < p_c1 or s_c2 > p_c2
elif side in ("left", "right"):
has_span_override = s_r1 < p_r1 or s_r2 > p_r2
else:
return None
if not has_span_override:
return None
vmin, vmax = float("inf"), float("-inf")
for other_ax in self.figure.axes:
if getattr(other_ax, "_panel_side", None):
continue
oss = getattr(other_ax, "get_subplotspec", lambda: None)()
if oss is None:
continue
oss = oss.get_topmost_subplotspec()
if oss.get_gridspec() is not gs:
continue
o_r1, o_r2, o_c1, o_c2 = oss._get_rows_columns(ncols=gs.ncols_total)
opos = other_ax.get_position()
if side in ("left", "right"):
if o_r1 >= s_r1 and o_r2 <= s_r2:
vmin = min(vmin, opos.y0)
vmax = max(vmax, opos.y1)
else:
if o_c1 >= s_c1 and o_c2 <= s_c2:
vmin = min(vmin, opos.x0)
vmax = max(vmax, opos.x1)
return (vmin, vmax) if vmin < vmax else None
@staticmethod
def _compute_adjusted_panel_pos(
side, panel_pos, span_extent, original_pos, main_pos, sx, sy, tol
):
"""
Compute the new [x0, y0, width, height] for a panel on the given side,
accounting for aspect-adjusted main axes and optional span extent.
Returns the new position list, or None for unknown sides.
"""
# NOTE: This will move to a layout composer in a future refactor.
ox0, oy0 = original_pos.x0, original_pos.y0
ox1, oy1 = original_pos.x1, original_pos.y1
mx0, my0 = main_pos.x0, main_pos.y0
px0, py0 = panel_pos.x0, panel_pos.y0
px1, py1 = panel_pos.x1, panel_pos.y1
if side in ("left", "right"):
# Compute vertical extent
if span_extent is not None:
along_y0 = span_extent[0]
along_h = span_extent[1] - span_extent[0]
elif py0 <= oy0 + tol and py1 >= oy1 - tol:
along_y0, along_h = my0, main_pos.height
else:
along_y0 = my0 + (panel_pos.y0 - oy0) * sy
along_h = panel_pos.height * sy
if side == "left":
gap = original_pos.x0 - (panel_pos.x0 + panel_pos.width)
new_x0 = main_pos.x0 - panel_pos.width - gap
else:
gap = panel_pos.x0 - (original_pos.x0 + original_pos.width)
new_x0 = main_pos.x0 + main_pos.width + gap
return [new_x0, along_y0, panel_pos.width, along_h]
elif side in ("top", "bottom"):
# Compute horizontal extent
if span_extent is not None:
along_x0 = span_extent[0]
along_w = span_extent[1] - span_extent[0]
elif px0 <= ox0 + tol and px1 >= ox1 - tol:
along_x0, along_w = mx0, main_pos.width
else:
along_x0 = mx0 + (panel_pos.x0 - ox0) * sx
along_w = panel_pos.width * sx
if side == "top":
gap = panel_pos.y0 - (original_pos.y0 + original_pos.height)
new_y0 = main_pos.y0 + main_pos.height + gap
else:
gap = original_pos.y0 - (panel_pos.y0 + panel_pos.height)
new_y0 = main_pos.y0 - panel_pos.height - gap
return [along_x0, new_y0, along_w, panel_pos.height]
return None
def _adjust_panel_positions(self, *, tol: float = 1e-9) -> None:
"""
Adjust panel positions to align with the aspect-constrained main axes.
After apply_aspect() shrinks the main axes, panels should flank the actual
map boundaries rather than the full gridspec allocation.
"""
# NOTE: This will move to a layout composer in a future refactor.
if not getattr(self, "_panel_dict", None):
return # no panels to adjust
# Current (aspect-adjusted) position
main_pos = getattr(self, "_position", None) or self.get_position()
# Subplot-spec position before apply_aspect(). This is the true "gridspec slot"
# and remains well-defined even if we temporarily modify axes positions.
ss = getattr(self, "get_subplotspec", lambda: None)()
original_pos = ss.get_position(self.figure) if ss is not None else None
if original_pos is None:
original_pos = getattr(
self, "_originalPosition", None
) or self.get_position(original=True)
# Only adjust if apply_aspect() actually changed the position (tolerance
# avoids float churn that can trigger unnecessary layout updates).
if (
abs(main_pos.x0 - original_pos.x0) <= tol
and abs(main_pos.y0 - original_pos.y0) <= tol
and abs(main_pos.width - original_pos.width) <= tol
and abs(main_pos.height - original_pos.height) <= tol
):
return
# Map original -> adjusted coordinates (only along the "long" axis of the
# panel, so span overrides across subplot rows/cols are preserved).
sx = main_pos.width / original_pos.width if original_pos.width else 1.0
sy = main_pos.height / original_pos.height if original_pos.height else 1.0
# Detect span overrides by comparing SubplotSpec extents of parent vs panels
parent_ss = getattr(self, "get_subplotspec", lambda: None)()
if parent_ss is not None:
parent_ss = parent_ss.get_topmost_subplotspec()
gs = parent_ss.get_gridspec()
p_r1, p_r2, p_c1, p_c2 = parent_ss._get_rows_columns(ncols=gs.ncols_total)
else:
gs = None
p_r1 = p_r2 = p_c1 = p_c2 = None
for side, panels in self._panel_dict.items():
for panel in panels:
# Use the panel subplot-spec box as the baseline (not its current
# original position) to avoid accumulated adjustments.
ss = getattr(panel, "get_subplotspec", lambda: None)()
panel_pos = ss.get_position(panel.figure) if ss is not None else None
if panel_pos is None:
panel_pos = panel.get_position(original=True)
span_extent = self._compute_span_extent(
side, panel, gs, p_r1, p_r2, p_c1, p_c2
)
new_pos = self._compute_adjusted_panel_pos(
side,
panel_pos,
span_extent,
original_pos,
main_pos,
sx,
sy,
tol,
)
if new_pos is None:
continue
# Panels typically have aspect='auto', which causes matplotlib to
# reset their *active* position to their *original* position inside
# apply_aspect()/get_position(). Update both so the change persists.
setter = getattr(panel, "_set_position", panel.set_position)
try:
setter(new_pos, which="both")
except TypeError: # older matplotlib
setter(new_pos)
def _get_gridliner_labels(
self,
bottom: bool | str | None = None,
top: bool | str | None = None,
left: bool | str | None = None,
right: bool | str | None = None,
) -> dict[str, list[mtext.Text]]:
adapter = self._gridliner_adapter("major")
if adapter is None:
return {}
return adapter.labels_for_sides(
bottom=bottom,
top=top,
left=left,
right=right,
)
def _toggle_gridliner_labels(
self,
labeltop: bool | str | None = None,
labelbottom: bool | str | None = None,
labelleft: bool | str | None = None,
labelright: bool | str | None = None,
geo: bool | str | None = None,
) -> None:
"""
Toggle visibility of gridliner labels for each direction via the backend
adapter.
Parameters
----------
labeltop, labelbottom, labelleft, labelright : bool or None
Whether to show labels on each side. If None, do not change.
geo : optional
Not used in this method.
"""
adapter = self._gridliner_adapter("major")
if adapter is None:
return
adapter.toggle_labels(
labelleft=labelleft,
labelright=labelright,
labelbottom=labelbottom,
labeltop=labeltop,
geo=geo,
)
@override
def _is_ticklabel_on(self, side: str) -> bool:
"""
Check if tick labels are visible on the requested side via the backend adapter.
"""
adapter = self._gridliner_adapter("major")
if adapter is None:
return False
return adapter.is_label_on(side)
def _clear_edge_lon_labels(self) -> None:
for label in self._edge_lon_labels:
try:
label.remove()
except Exception:
pass
self._edge_lon_labels = []
def _sync_edge_lon_labels(self) -> None:
"""
Ensure cartopy top longitude labels include the endpoints when requested.
"""
if self._name != "cartopy" or ccrs is None or not self._is_rectilinear():
self._clear_edge_lon_labels()
return
adapter = self._gridliner_adapter("major", create=False)
if adapter is None or not adapter.is_label_on("labeltop"):
self._clear_edge_lon_labels()
return
top_labels = adapter.labels_for_sides(top=True).get("top", [])
if not top_labels:
# No top labels are enabled; avoid adding extras.
self._clear_edge_lon_labels()
return
ticks = np.asarray(self._get_lonticklocs(which="major"))
if ticks.size == 0:
self._clear_edge_lon_labels()
return
# No extra labels; endpoints are intentionally dropped to avoid crowding.
self._clear_edge_lon_labels()
def _clear_edge_lat_labels(self) -> None:
for label in self._edge_lat_labels:
try:
label.remove()
except Exception:
pass
self._edge_lat_labels = []
def _sync_edge_lat_labels(self) -> None:
"""
Ensure cartopy left/right latitude labels include the endpoints when requested.
"""
if self._name != "cartopy" or ccrs is None or not self._is_rectilinear():
self._clear_edge_lat_labels()
return
adapter = self._gridliner_adapter("major", create=False)
if adapter is None:
self._clear_edge_lat_labels()
return
left_on = adapter.is_label_on("labelleft")
right_on = adapter.is_label_on("labelright")
if not left_on and not right_on:
self._clear_edge_lat_labels()
return
left_labels = (
adapter.labels_for_sides(left=True).get("left", []) if left_on else []
)
right_labels = (
adapter.labels_for_sides(right=True).get("right", []) if right_on else []
)
if not left_labels and not right_labels:
self._clear_edge_lat_labels()
return
ticks = np.asarray(self._get_latticklocs(which="major"))
if ticks.size == 0:
self._clear_edge_lat_labels()
return
# No extra labels; endpoints are intentionally dropped to avoid crowding.
self._clear_edge_lat_labels()
def _prune_corner_labels(self) -> bool:
"""
Drop endpoint labels at the map corners to reduce crowding.
"""
if self._name != "cartopy" or ccrs is None or not self._is_rectilinear():
return False
adapter = self._gridliner_adapter("major", create=False)
if adapter is None:
return False
eps = 1e-6
lon_ticks = np.asarray(self._get_lonticklocs(which="major"))
lat_ticks = np.asarray(self._get_latticklocs(which="major"))
changed = False
if lon_ticks.size:
lon_ends = (lon_ticks[0], lon_ticks[-1])
for side in ("top", "bottom"):
labels = adapter.labels_for_sides(**{side: True}).get(side, [])
for label in labels:
x, _ = label.get_position()
if any(np.isclose(x, end, atol=eps) for end in lon_ends):
if label.get_visible():
label.set_visible(False)
changed = True
if lat_ticks.size:
lat_ends = (lat_ticks[0], lat_ticks[-1])
for side in ("left", "right"):
labels = adapter.labels_for_sides(**{side: True}).get(side, [])
for label in labels:
_, y = label.get_position()
if any(np.isclose(y, end, atol=eps) for end in lat_ends):
if label.get_visible():
label.set_visible(False)
changed = True
return changed
[docs]
@override
def draw(self, renderer: Any = None, *args: Any, **kwargs: Any) -> None:
# Perform extra post-processing steps
# NOTE: In *principle* axis sharing application step goes here. But should
# already be complete because auto_layout() (called by figure pre-processor)
# has to run it before aligning labels. So this is harmless no-op.
self._apply_axis_sharing()
self._sync_edge_lon_labels()
self._sync_edge_lat_labels()
super().draw(renderer, *args, **kwargs)
# Prune after draw so cartopy has created label artists.
if self._prune_corner_labels():
self.stale = True
def _get_lonticklocs(self, which: str = "major") -> np.ndarray:
"""
Retrieve longitude tick locations.
"""
# Get tick locations from dummy axes
# NOTE: This is workaround for: https://github.com/SciTools/cartopy/issues/1564
# Since _axes_domain is wrong we determine tick locations ourselves with
# more accurate extent tracked by _LatAxis and _LonAxis.
axis = self._lonaxis
if which == "major":
lines = axis.get_majorticklocs()
else:
lines = axis.get_minorticklocs()
return lines
def _get_latticklocs(self, which: str = "major") -> np.ndarray:
"""
Retrieve latitude tick locations.
"""
axis = self._lataxis
if which == "major":
lines = axis.get_majorticklocs()
else:
lines = axis.get_minorticklocs()
return lines
def _set_view_intervals(self, extent: Sequence[float]) -> None:
"""
Update view intervals for lon and lat axis.
"""
self._lonaxis.set_view_interval(*extent[:2])
self._lataxis.set_view_interval(*extent[2:])
@staticmethod
def _to_label_array(arg: Any, lon: bool = True) -> list[bool | None]:
"""
Convert labels argument to length-5 boolean array.
"""
array = arg
which = "lon" if lon else "lat"
array = np.atleast_1d(array).tolist()
if len(array) == 1 and array[0] is None:
array = [None] * 5
elif all(isinstance(_, str) for _ in array):
strings = array # iterate over list of strings
array = [False] * 5
opts = ("left", "right", "bottom", "top", "geo")
for string in strings:
string = string.replace("left", "l")
string = string.replace("right", "r")
string = string.replace("bottom", "b")
string = string.replace("top", "t")
if string == "all":
string = "lrbt"
elif string == "both":
string = "bt" if lon else "lr"
elif string == "neither":
string = ""
elif string in opts:
string = string[0]
if set(string) - set("lrbtg"):
raise ValueError(
f"Invalid {which}label string {string!r}. Must be one of "
+ ", ".join(map(repr, (*opts, "neither", "both", "all")))
+ " or a string of single-letter characters like 'lr'."
)
for char in string:
array["lrbtg".index(char)] = True
if rc["grid.geolabels"] and any(array):
# Geo labels only apply if any edge labels are enabled.
array[4] = True # possibly toggle geo spine labels
elif not any(isinstance(_, str) for _ in array):
if len(array) == 1:
array.append(None)
if len(array) == 2:
array = [None, None, *array] if lon else [*array, None, None]
if len(array) == 4:
b = (
any(a for a in array if a is not None)
if rc["grid.geolabels"]
else None
)
array.append(b)
if len(array) != 5:
raise ValueError(f"Invald boolean label array length {len(array)}.")
else:
raise ValueError(f"Invalid {which}label spec: {arg}.")
return array
def _format_init_basemap_boundary(self) -> None:
"""
Initialize basemap boundaries before format triggers gridline work.
Basemap can create a hidden boundary when gridlines are drawn before the
map boundary is initialized, so we force initialization here.
"""
if self._name != "basemap" or self._map_boundary is not None:
return
if self.projection.projection in self._proj_non_rectangular:
patch = self.projection.drawmapboundary(ax=self)
self._map_boundary = patch
else:
self.projection.set_axes_limits(self) # initialize aspect ratio
self._map_boundary = object() # sentinel
def _format_rc_context(
self,
kwargs: MutableMapping[str, Any],
*,
ticklen: Any,
labelcolor: Any,
labelsize: Any,
labelweight: Any,
) -> tuple[dict[str, Any], int, Any]:
"""
Pop rc overrides and prepare context settings for format().
"""
rc_kw, rc_mode = _pop_rc(kwargs)
ticklen = _not_none(ticklen, rc_kw.get("tick.len", None))
labelcolor = _not_none(labelcolor, kwargs.get("color", None))
if labelcolor is not None:
rc_kw["grid.labelcolor"] = labelcolor
if labelsize is not None:
rc_kw["grid.labelsize"] = labelsize
if labelweight is not None:
rc_kw["grid.labelweight"] = labelweight
return rc_kw, rc_mode, ticklen
def _format_normalize_label_inputs(
self,
*,
labels: Any,
lonlabels: Any,
latlabels: Any,
loninline: bool | None,
latinline: bool | None,
inlinelabels: bool | None,
) -> tuple[Any, Any]:
"""
Normalize label inputs before rc context is applied.
"""
lonlabels = _not_none(lonlabels, labels)
latlabels = _not_none(latlabels, labels)
if "0.18" <= _version_cartopy < "0.20":
lonlabels = _not_none(lonlabels, loninline, inlinelabels)
latlabels = _not_none(latlabels, latinline, inlinelabels)
return lonlabels, latlabels
def _format_resolve_label_arrays(
self, *, labels: Any, lonlabels: Any, latlabels: Any
) -> tuple[Any, Any, list[bool | None], list[bool | None]]:
"""
Resolve label toggles and return label arrays for gridliners.
"""
if lonlabels is None and latlabels is None:
labels = _not_none(labels, rc.find("grid.labels", context=True))
lonlabels = labels
latlabels = labels
else:
lonlabels = _not_none(lonlabels, labels)
latlabels = _not_none(latlabels, labels)
self._toggle_ticks(lonlabels, "x")
self._toggle_ticks(latlabels, "y")
lonarray = self._to_label_array(lonlabels, lon=True)
latarray = self._to_label_array(latlabels, lon=False)
return lonlabels, latlabels, lonarray, latarray
def _format_update_latmax(self, latmax: float | None) -> None:
"""
Update the latitude gridline cutoff.
"""
latmax = _not_none(latmax, rc.find("grid.latmax", context=True))
if latmax is not None:
self._lataxis.set_latmax(latmax)
def _format_update_major_locators(
self,
*,
lonlocator: Any,
lonlines: Any,
latlocator: Any,
latlines: Any,
lonlocator_kw: MutableMapping | None,
lonlines_kw: MutableMapping | None,
latlocator_kw: MutableMapping | None,
latlines_kw: MutableMapping | None,
) -> None:
"""
Update major longitude/latitude locators.
"""
lonlocator = _not_none(lonlocator=lonlocator, lonlines=lonlines)
latlocator = _not_none(latlocator=latlocator, latlines=latlines)
if lonlocator is not None:
lonlocator_kw = _not_none(
lonlocator_kw=lonlocator_kw,
lonlines_kw=lonlines_kw,
default={},
)
locator = constructor.Locator(lonlocator, **lonlocator_kw)
self._lonaxis.set_major_locator(locator)
if latlocator is not None:
latlocator_kw = _not_none(
latlocator_kw=latlocator_kw,
latlines_kw=latlines_kw,
default={},
)
locator = constructor.Locator(latlocator, **latlocator_kw)
self._lataxis.set_major_locator(locator)
def _format_update_minor_locators(
self,
*,
lonminorlocator: Any,
lonminorlines: Any,
latminorlocator: Any,
latminorlines: Any,
lonminorlocator_kw: MutableMapping | None,
lonminorlines_kw: MutableMapping | None,
latminorlocator_kw: MutableMapping | None,
latminorlines_kw: MutableMapping | None,
) -> None:
"""
Update minor longitude/latitude locators.
"""
lonminorlocator = _not_none(
lonminorlocator=lonminorlocator, lonminorlines=lonminorlines
)
latminorlocator = _not_none(
latminorlocator=latminorlocator, latminorlines=latminorlines
)
if lonminorlocator is not None:
lonminorlocator_kw = _not_none(
lonminorlocator_kw=lonminorlocator_kw,
lonminorlines_kw=lonminorlines_kw,
default={},
)
locator = constructor.Locator(lonminorlocator, **lonminorlocator_kw)
self._lonaxis.set_minor_locator(locator)
if latminorlocator is not None:
latminorlocator_kw = _not_none(
latminorlocator_kw=latminorlocator_kw,
latminorlines_kw=latminorlines_kw,
default={},
)
locator = constructor.Locator(latminorlocator, **latminorlocator_kw)
self._lataxis.set_minor_locator(locator)
def _format_resolve_gridline_params(
self,
*,
loninline: bool | None,
latinline: bool | None,
inlinelabels: bool | None,
rotatelabels: bool | None,
labelrotation: float | None,
lonlabelrotation: float | None,
latlabelrotation: float | None,
labelpad: Any,
dms: bool | None,
nsteps: int | None,
) -> tuple[
bool | None,
bool | None,
bool | None,
float | None,
float | None,
Any,
bool | None,
int | None,
]:
"""
Resolve gridline-related parameters with rc defaults.
"""
loninline = _not_none(
loninline, inlinelabels, rc.find("grid.inlinelabels", context=True)
)
latinline = _not_none(
latinline, inlinelabels, rc.find("grid.inlinelabels", context=True)
)
rotatelabels = _not_none(
rotatelabels, rc.find("grid.rotatelabels", context=True)
)
lonlabelrotation = _not_none(lonlabelrotation, labelrotation)
latlabelrotation = _not_none(latlabelrotation, labelrotation)
labelpad = _not_none(labelpad, rc.find("grid.labelpad", context=True))
dms = _not_none(dms, rc.find("grid.dmslabels", context=True))
nsteps = _not_none(nsteps, rc.find("grid.nsteps", context=True))
return (
loninline,
latinline,
rotatelabels,
lonlabelrotation,
latlabelrotation,
labelpad,
dms,
nsteps,
)
def _format_update_formatters(
self,
*,
lonformatter: Any,
latformatter: Any,
lonformatter_kw: MutableMapping | None,
latformatter_kw: MutableMapping | None,
dms: bool | None,
) -> None:
"""
Update longitude/latitude formatters and DMS flags.
"""
if lonformatter is not None:
lonformatter_kw = lonformatter_kw or {}
formatter = constructor.Formatter(lonformatter, **lonformatter_kw)
self._lonaxis.set_major_formatter(formatter)
if latformatter is not None:
latformatter_kw = latformatter_kw or {}
formatter = constructor.Formatter(latformatter, **latformatter_kw)
self._lataxis.set_major_formatter(formatter)
if dms is not None: # harmless if these are not GeoLocators
self._lonaxis.get_major_formatter()._dms = dms
self._lataxis.get_major_formatter()._dms = dms
self._lonaxis.get_major_locator()._dms = dms
self._lataxis.get_major_locator()._dms = dms
def _format_apply_grid_updates(
self,
*,
lonlim: tuple[float | None, float | None] | None,
latlim: tuple[float | None, float | None] | None,
boundinglat: float | None,
longrid: bool | None,
latgrid: bool | None,
longridminor: bool | None,
latgridminor: bool | None,
lonarray: Sequence[bool | None],
latarray: Sequence[bool | None],
loninline: bool | None,
latinline: bool | None,
rotatelabels: bool | None,
lonlabelrotation: float | None,
latlabelrotation: float | None,
labelpad: Any,
nsteps: int | None,
) -> tuple[tuple[float | None, float | None], tuple[float | None, float | None]]:
"""
Apply extent, features, and gridline updates for format().
"""
lonlim = _not_none(lonlim, default=(None, None))
latlim = _not_none(latlim, default=(None, None))
self._update_extent(lonlim=lonlim, latlim=latlim, boundinglat=boundinglat)
self._update_features()
self._update_major_gridlines(
longrid=longrid,
latgrid=latgrid, # gridline toggles
lonarray=lonarray,
latarray=latarray, # label toggles
loninline=loninline,
latinline=latinline,
rotatelabels=rotatelabels,
lonlabelrotation=lonlabelrotation,
latlabelrotation=latlabelrotation,
labelpad=labelpad,
nsteps=nsteps,
)
self._update_minor_gridlines(
longrid=longridminor,
latgrid=latgridminor,
nsteps=nsteps,
)
return lonlim, latlim
def _format_apply_ticklen(
self,
*,
lonlim: tuple[float | None, float | None],
latlim: tuple[float | None, float | None],
boundinglat: float | None,
ticklen: Any,
lonticklen: Any,
latticklen: Any,
) -> None:
"""
Apply tick length updates, including any extent refresh for geoticks.
"""
lonticklen = _not_none(lonticklen, ticklen)
latticklen = _not_none(latticklen, ticklen)
if lonticklen or latticklen:
# Only add warning when ticks are given
if _is_rectilinear_projection(self):
self._add_geoticks("x", lonticklen, ticklen)
self._add_geoticks("y", latticklen, ticklen)
# If latlim is set to None it resets
# the view; this affects the visible range
# we need to force this to prevent
# side effects
if latlim == (None, None):
latlim = self._lataxis.get_view_interval()
if lonlim == (None, None):
lonlim = self._lonaxis.get_view_interval()
self._update_extent(
lonlim=lonlim, latlim=latlim, boundinglat=boundinglat
)
else:
warnings._warn_ultraplot(
f"Projection is not rectilinear. Ignoring {lonticklen=} and {latticklen=} settings."
)
# Format flow:
# 1) init basemap boundary
# 2) enter rc context and resolve label/locator/formatter inputs
# 3) apply extent, features, and gridlines
# 4) apply tick lengths and defer to parent format
[docs]
@docstring._snippet_manager
def choropleth(
self,
geometries: Sequence[Any],
values: Sequence[Any] | None = None,
*,
transform: Any = None,
country: bool = False,
country_reso: str | None = None,
country_territories: bool | None = None,
colorbar: Any = None,
colorbar_kw: MutableMapping[str, Any] | None = None,
missing_kw: MutableMapping[str, Any] | None = None,
**kwargs: Any,
) -> mcollections.PatchCollection:
"""
%(geo.choropleth)s
"""
country_reso = _not_none(
country_reso,
rc.find("geo.choropleth.country_reso", context=True),
)
country_territories = _not_none(
country_territories,
rc.find("geo.choropleth.country_territories", context=True),
)
if country:
geometries, values, transform = _choropleth_country_inputs(
geometries,
values,
transform=transform,
resolution=country_reso,
include_far=country_territories,
)
elif values is None:
raise ValueError(
"choropleth() requires values unless country=True and geometries "
"is a mapping of country identifiers to values."
)
geometries = list(geometries)
values_arr = np.ma.masked_invalid(np.asarray(values, dtype=float).ravel())
if values_arr.ndim != 1:
raise ValueError("choropleth() values must be one-dimensional.")
if len(geometries) != values_arr.size:
raise ValueError(
"choropleth() geometries and values must have the same length. "
f"Got {len(geometries)} geometries and {values_arr.size} values."
)
kw = kwargs.copy()
kw.update(_pop_props(kw, "collection"))
center_levels = kw.pop("center_levels", None)
explicit_zorder = "zorder" in kwargs
zorder = _not_none(
kw.get("zorder", None),
rc.find("geo.choropleth.zorder", context=True),
rc["land.zorder"] + 0.1,
)
kw["zorder"] = zorder
invalid_face_keys = ("color", "colors", "facecolor", "facecolors")
ignored = {key: kw.pop(key) for key in invalid_face_keys if key in kw}
if ignored:
warnings._warn_ultraplot(
"choropleth() colors polygons from numeric values, so "
f"facecolor/color args are ignored: {tuple(ignored)}. "
"Use cmap=... or missing_kw=... instead."
)
valid_patches = []
valid_values = []
missing_patches = []
valid_mask = ~np.ma.getmaskarray(values_arr)
for geometry, value, is_valid in zip(geometries, values_arr.data, valid_mask):
path = _choropleth_geometry_path(self, geometry, transform=transform)
if path is None:
continue
patch = mpatches.PathPatch(path)
if is_valid:
valid_patches.append(patch)
valid_values.append(float(value))
else:
missing_patches.append(patch)
if not valid_patches:
raise ValueError("choropleth() produced no polygon patches to draw.")
valid_values = np.asarray(valid_values, dtype=float)
kw = self._parse_cmap(
valid_values,
default_discrete=True,
center_levels=center_levels,
**kw,
)
cmap, norm = kw.pop("cmap"), kw.pop("norm")
guide_kw = _pop_params(kw, self._update_guide)
label = kw.pop("label", None)
collection = mcollections.PatchCollection(
valid_patches,
cmap=cmap,
norm=norm,
label=label,
match_original=False,
)
collection.set_array(valid_values)
collection.update(kw)
self.add_collection(collection)
edge_kw = _choropleth_edge_collection_kw(
kw,
zorder=collection.get_zorder(),
explicit_zorder=explicit_zorder,
)
if edge_kw is not None:
edge_collection = mcollections.PatchCollection(
valid_patches,
match_original=False,
)
edge_collection.update(edge_kw)
self.add_collection(edge_collection)
if missing_patches and missing_kw is not None:
miss_kw = dict(missing_kw)
miss_kw.update(_pop_props(miss_kw, "collection"))
missing_explicit_zorder = "zorder" in missing_kw
if not any(key in miss_kw for key in invalid_face_keys):
miss_kw["facecolor"] = "none"
missing = mcollections.PatchCollection(
missing_patches,
match_original=False,
)
missing.update(miss_kw)
self.add_collection(missing)
miss_edge_kw = _choropleth_edge_collection_kw(
miss_kw,
zorder=missing.get_zorder(),
explicit_zorder=missing_explicit_zorder,
)
if miss_edge_kw is not None:
missing_edge = mcollections.PatchCollection(
missing_patches,
match_original=False,
)
missing_edge.update(miss_edge_kw)
self.add_collection(missing_edge)
self.autoscale_view()
self._update_guide(collection, queue_colorbar=False, **guide_kw)
if colorbar:
self.colorbar(collection, loc=colorbar, **(colorbar_kw or {}))
return collection
def _add_geoticks(self, x_or_y: str, itick: Any, ticklen: Any) -> None:
"""
Add tick marks to the geographic axes.
Parameters
----------
x_or_y : {'x', 'y'}
The axis to add ticks to ('x' for longitude, 'y' for latitude).
itick, ticklen : unit-spec, default: :rc:`tick.len`
Major tick lengths for the x and y axis.
%(units.pt)s
Use the argument `ticklen` to set both at once.
Notes
-----
This method handles proper tick mark drawing for geographic projections
while respecting the current gridline settings.
"""
size = _not_none(itick, ticklen)
# Skip if no tick size specified
if size is None:
return
# Convert unit spec to points and apply rc scaling factor.
size = units(size) * rc["tick.len"]
ax = getattr(self, f"{x_or_y}axis")
# Get the tick positions based on the backend gridliner (adapter-aware).
adapter = self._gridliner_adapter("major")
is_basemap = self._name == "basemap"
tick_positions = self._gridliner_tick_positions(x_or_y, which="major")
if is_basemap:
# Turn off the ticks otherwise they are double for basemap.
ax.set_major_formatter(mticker.NullFormatter())
# Always show the ticks
ax.set_ticks(tick_positions)
ax.set_visible(True)
# Note: set grid_alpha to 0 as it is controlled through the gridlines_major
# object (which is not the same ticker)
params = ax.get_tick_params()
# Minor ticks are shortened relative to major ticks.
sizes = [
size,
_MINOR_TICK_SCALE * size if isinstance(size, (int, float)) else size,
]
for size, which in zip(sizes, ["major", "minor"]):
params.update({"length": size})
params.pop("grid_alpha", None)
# Avoid overriding gridliner label toggles via tick_params defaults.
for key in ("labeltop", "labelbottom", "labelleft", "labelright"):
params.pop(key, None)
self.tick_params(
axis=x_or_y,
which=which,
grid_alpha=0,
**params,
)
# Apply tick parameters
# Move the labels outwards if specified
gl = getattr(self, "_gridlines_major", None)
if gl is not None and hasattr(gl, f"{x_or_y}padding"):
# Cartopy gridliner padding is in points; scale matches tick size visually.
setattr(gl, f"{x_or_y}padding", _GRIDLINER_PAD_SCALE * size)
elif is_basemap and isinstance(adapter, _BasemapGridlinerAdapter):
# For basemap backends, emulate the label placement like cartopy.
self._add_gridline_labels(
ax, (adapter.lonlines, adapter.latlines), padding=size
)
self.stale = True
def _add_gridline_labels(
self,
ax: maxis.Axis,
gl: tuple[GridlineDict, GridlineDict],
padding: float | int = 8,
) -> None:
"""
This function is intended for the Basemap backend
and mirrors the label placement behavior of Cartopy.
See: https://cartopy.readthedocs.io/stable/reference/generated/cartopy.mpl.gridliner.Gridliner.html
"""
sides = dict()
for which, formatter in zip("xy", gl):
for loc, (lines, labels) in formatter.items():
for i, label in enumerate(labels):
upper_end = True
position = label.get_position()
if which == "x":
if position[1] < 0:
upper_end = False
elif which == "y":
if position[0] < 0:
upper_end = False
line = lines[0] if upper_end else lines[-1]
shift_scale = 1 if upper_end else -1
path = line.get_path()
vertices = path.vertices
label.set_transform(line.get_transform())
if len(ax.get_major_ticks()) == 0:
continue
# Get correct line
tick = ax.get_major_ticks()[0]
which_line = 1 if shift_scale == 1 else 2
tickline = getattr(tick, f"tick{which_line}line")
position = np.array(label.get_position())
# Convert points to display units using DPI (72 points per inch).
size = (
_BASEMAP_LABEL_SIZE_SCALE
* (tick._size + label.get_fontsize() + padding)
* self.figure.dpi
/ 72
)
offset = vertices[0]
if upper_end:
offset = vertices[-1]
if which == "x":
# Move y position
# Empirical scaling to mimic cartopy label spacing.
position[1] = (
offset[1] + shift_scale * size * _BASEMAP_LABEL_Y_SCALE
)
ha = "center"
va = "top" if shift_scale == 1 else "bottom"
if shift_scale == 1:
sides.setdefault("top", []).append(label)
else:
sides.setdefault("bottom", []).append(label)
else:
# Move x position
# Empirical scaling to mimic cartopy label spacing.
position[0] = (
offset[0] + shift_scale * size * _BASEMAP_LABEL_X_SCALE
)
ha = "left" if shift_scale == 1 else "right"
va = "center"
if shift_scale == 1:
sides.setdefault("right", []).append(label)
else:
sides.setdefault("left", []).append(label)
label.set_position(position)
label.set_horizontalalignment(ha)
label.set_verticalalignment(va)
# Some labels are double in the list not sure why
# Remove them for now
for key, labels in sides.items():
seen = set()
for label in labels:
pos = label.get_position()
txt = label.get_text()
if (pos, txt) not in seen:
seen.add((pos, txt))
else:
label.set_visible(False)
@property
def gridlines_major(self) -> Any:
"""
The cartopy `~cartopy.mpl.gridliner.Gridliner`
used for major gridlines or a 2-tuple containing the
(longitude, latitude) major gridlines returned by
basemap's :func:`~mpl_toolkits.basemap.Basemap.drawmeridians`
and :func:`~mpl_toolkits.basemap.Basemap.drawparallels`.
This can be used for customization and debugging.
"""
# Refresh adapters so external access sees up-to-date gridliner state.
builder = getattr(self, "_build_gridliner_adapter", None)
if builder is not None:
self._set_gridliner_adapter("major", builder("major"))
if self._name == "basemap":
return (self._lonlines_major, self._latlines_major)
else:
return self._gridlines_major
@property
def gridlines_minor(self) -> Any:
"""
The cartopy `~cartopy.mpl.gridliner.Gridliner`
used for minor gridlines or a 2-tuple containing the
(longitude, latitude) minor gridlines returned by
basemap's :func:`~mpl_toolkits.basemap.Basemap.drawmeridians`
and :func:`~mpl_toolkits.basemap.Basemap.drawparallels`.
This can be used for customization and debugging.
"""
# Refresh adapters so external access sees up-to-date gridliner state.
builder = getattr(self, "_build_gridliner_adapter", None)
if builder is not None:
self._set_gridliner_adapter("minor", builder("minor"))
if self._name == "basemap":
return (self._lonlines_minor, self._latlines_minor)
else:
return self._gridlines_minor
@property
def projection(self) -> Any:
"""
The cartopy `~cartopy.crs.Projection` or basemap `~mpl_toolkits.basemap.Basemap`
instance associated with this axes.
"""
return self._map_projection
@projection.setter
def projection(self, map_projection: Any) -> None:
cls = self._proj_class
if not isinstance(map_projection, cls):
raise ValueError(f"Projection must be a {cls} instance.")
self._map_projection = map_projection
if hasattr(self, "_lonaxis") or hasattr(self, "_lataxis"):
# Update the projection of the lon and lat axes
self._lonaxis.get_major_formatter()._source_projection = map_projection
self._lataxis.get_major_formatter()._source_projection = map_projection
class _CartopyAxes(GeoAxes, _GeoAxes):
"""
Axes subclass for plotting cartopy projections.
"""
_name = "cartopy"
_name_aliases = ("geo", "geographic") # default 'geographic' axes
_proj_class = Projection
_PANEL_TOL = 1e-9
_proj_north = (
pproj.NorthPolarStereo,
pproj.NorthPolarGnomonic,
pproj.NorthPolarAzimuthalEquidistant,
pproj.NorthPolarLambertAzimuthalEqualArea,
)
_proj_south = (
pproj.SouthPolarStereo,
pproj.SouthPolarGnomonic,
pproj.SouthPolarAzimuthalEquidistant,
pproj.SouthPolarLambertAzimuthalEqualArea,
)
_proj_polar = _proj_north + _proj_south
# NOTE: The rename argument wrapper belongs here instead of format() because
# these arguments were previously only accepted during initialization.
@warnings._rename_kwargs("0.10", circular="round", autoextent="extent")
def __init__(self, *args: Any, map_projection: Any = None, **kwargs: Any) -> None:
"""
Parameters
----------
map_projection : ~cartopy.crs.Projection
The map projection.
*args, **kwargs
Passed to `GeoAxes`.
"""
# Initialize axes. Note that critical attributes like outline_patch
# needed by _format_apply are added before it is called.
import cartopy # noqa: F401 verify package is available
self.projection = map_projection # verify
polar = isinstance(self.projection, self._proj_polar)
latmax = 80 if polar else 90 # default latmax
self._is_round = False
self._boundinglat = None # NOTE: must start at None so _update_extent acts
self._gridlines_major = None
self._gridlines_minor = None
self._lonaxis = _LonAxis(self)
self._lataxis = _LatAxis(self, latmax=latmax)
# 'map_projection' argument is deprecated since cartopy 0.21 and
# replaced by 'projection'.
if _version_cartopy >= "0.21":
super().__init__(*args, projection=self.projection, **kwargs)
else:
super().__init__(*args, map_projection=self.projection, **kwargs)
for axis in (self.xaxis, self.yaxis):
axis.set_tick_params(which="both", size=0) # prevent extra label offset
@staticmethod
def _get_circle_path(N: int = 100) -> mpath.Path:
"""
Return a circle `~matplotlib.path.Path` used as the outline for polar
stereographic, azimuthal equidistant, Lambert conformal, and gnomonic
projections. This was developed from `this cartopy example \
<https://cartopy.readthedocs.io/v0.25.0.post2/gallery/lines_and_polygons/always_circular_stereo.html>`__.
"""
theta = np.linspace(0, 2 * np.pi, N)
center, radius = [0.5, 0.5], 0.5
verts = np.vstack([np.sin(theta), np.cos(theta)]).T
return mpath.Path(verts * radius + center)
def _get_global_extent(self) -> list[float]:
"""
Return the global extent with meridian properly shifted.
"""
lon0 = self._get_lon0()
return [-180 + lon0, 180 + lon0, -90, 90]
def _get_lon0(self) -> float:
"""
Get the central longitude. Default is ``0``.
"""
return self.projection.proj4_params.get("lon_0", 0)
def gridlines(
self,
crs: Any = None,
draw_labels: bool | str | None = False,
xlocs: mticker.Locator | Sequence[float] | None = None,
ylocs: mticker.Locator | Sequence[float] | None = None,
dms: bool = False,
x_inline: bool | None = None,
y_inline: bool | None = None,
auto_inline: bool = True,
xformatter: Any = None,
yformatter: Any = None,
xlim: Sequence[float] | None = None,
ylim: Sequence[float] | None = None,
rotate_labels: bool | float | None = None,
xlabel_style: MutableMapping[str, Any] | None = None,
ylabel_style: MutableMapping[str, Any] | None = None,
labels_bbox_style: MutableMapping[str, Any] | None = None,
xpadding: float | None = 5,
ypadding: float | None = 5,
offset_angle: float = 25,
auto_update: bool | None = None,
formatter_kwargs: MutableMapping[str, Any] | None = None,
**kwargs: Any,
) -> _CartopyGridlinerProtocol:
"""
Override cartopy gridlines to use a local Gridliner subclass.
"""
if crs is None:
crs = ccrs.PlateCarree(globe=self.projection.globe)
gridliner_cls = _CartopyGridliner or cgridliner.Gridliner
gl = gridliner_cls(
self,
crs=crs,
draw_labels=draw_labels,
xlocator=xlocs,
ylocator=ylocs,
collection_kwargs=kwargs,
dms=dms,
x_inline=x_inline,
y_inline=y_inline,
auto_inline=auto_inline,
xformatter=xformatter,
yformatter=yformatter,
xlim=xlim,
ylim=ylim,
rotate_labels=rotate_labels,
xlabel_style=xlabel_style,
ylabel_style=ylabel_style,
labels_bbox_style=labels_bbox_style,
xpadding=xpadding,
ypadding=ypadding,
offset_angle=offset_angle,
auto_update=auto_update,
formatter_kwargs=formatter_kwargs,
)
self.add_artist(gl)
return gl
def _init_gridlines(self) -> _CartopyGridlinerProtocol:
"""
Create "major" and "minor" gridliners managed by ultraplot.
"""
# Return gridliner using our subclass to isolate cartopy quirks.
gl = self.gridlines(crs=ccrs.PlateCarree())
gl.xlines = gl.ylines = False
return gl
def _build_gridliner_adapter(
self, which: str = "major"
) -> Optional[_GridlinerAdapter]:
gl = getattr(self, f"_gridlines_{which}", None)
if gl is None:
return None
return _CartopyGridlinerAdapter(gl)
def _update_background(self, **kwargs: Any) -> None:
"""
Update the map background patches. This is called in `Axes.format`.
"""
# TODO: Understand issue where setting global linewidth puts map boundary on
# top of land patches, but setting linewidth with format() (even with separate
# format() calls) puts map boundary underneath. Zorder seems to be totally
# ignored and using spines vs. patch makes no difference.
# NOTE: outline_patch is redundant, use background_patch instead
kw_face, kw_edge = rc._get_background_props(native=False, **kwargs)
kw_face["linewidth"] = 0
kw_edge["facecolor"] = "none"
if _version_cartopy >= "0.18":
self.patch.update(kw_face)
self.spines["geo"].update(kw_edge)
else:
self.background_patch.update(kw_face)
self.outline_patch.update(kw_edge)
def _update_boundary(self, round: bool | None = None) -> None:
"""
Update the map boundary path.
"""
round = _not_none(round, rc.find("geo.round", context=True))
if round is None or not isinstance(self.projection, self._proj_polar):
pass
elif round:
self._is_round = True
self.set_boundary(self._get_circle_path(), transform=self.transAxes)
elif not round and self._is_round:
if hasattr(self, "_boundary"):
self._boundary()
else:
warnings._warn_ultraplot("Failed to reset round map boundary.")
def _update_extent_mode(
self, extent: str | None = None, boundinglat: float | None = None
) -> None:
"""
Update the extent mode.
"""
# NOTE: Use set_global rather than set_extent() or _update_extent() for
# simplicity. Uses projection.[xy]_limits which may not be strictly global.
# NOTE: For some reason initial call to _set_view_intervals may change the
# default boundary with extent='auto'. Try this in a robinson projection:
# ax.contour(np.linspace(-90, 180, N), np.linspace(0, 90, N), np.zeros(N, N))
extent = _not_none(extent, rc.find("geo.extent", context=True))
if extent is None:
return
if extent not in ("globe", "auto"):
raise ValueError(
f"Invalid extent mode {extent!r}. Must be 'auto' or 'globe'."
)
polar = isinstance(self.projection, self._proj_polar)
if not polar:
self.set_global()
else:
if isinstance(self.projection, pproj.NorthPolarGnomonic):
default_boundinglat = 30
elif isinstance(self.projection, pproj.SouthPolarGnomonic):
default_boundinglat = -30
else:
default_boundinglat = 0
boundinglat = _not_none(boundinglat, default_boundinglat)
self._update_extent(boundinglat=boundinglat)
if extent == "auto":
# NOTE: This will work even if applied after plotting stuff
# and fixing the limits. Very easy to toggle on and off.
self.set_autoscalex_on(True)
self.set_autoscaley_on(True)
def _update_extent(
self,
lonlim: tuple[float | None, float | None] | None = None,
latlim: tuple[float | None, float | None] | None = None,
boundinglat: float | None = None,
) -> None:
"""
Set the projection extent.
"""
# Projection extent
# NOTE: Lon axis and lat axis extents are updated by set_extent.
# WARNING: The set_extent method tries to set a *rectangle* between the *4*
# (x, y) coordinate pairs (each corner), so something like (-180, 180, -90, 90)
# will result in *line*, causing error! We correct this here.
eps_small = 1e-10 # bug with full -180, 180 range when lon_0 != 0
lon0 = self._get_lon0()
proj = type(self.projection).__name__
north = isinstance(self.projection, self._proj_north)
south = isinstance(self.projection, self._proj_south)
lonlim = _not_none(lonlim, (None, None))
latlim = _not_none(latlim, (None, None))
if north or south:
if any(_ is not None for _ in (*lonlim, *latlim)):
warnings._warn_ultraplot(
f'{proj!r} extent is controlled by "boundinglat", '
f"ignoring lonlim={lonlim!r} and latlim={latlim!r}."
)
if boundinglat is not None and boundinglat != self._boundinglat:
lat0 = 90 if north else -90
lon0 = self._get_lon0()
extent = [
lon0 - 180 + eps_small,
lon0 + 180 - eps_small,
boundinglat,
lat0,
]
self.set_extent(extent, crs=ccrs.PlateCarree())
self._boundinglat = boundinglat
# Rectangular extent
else:
if boundinglat is not None:
warnings._warn_ultraplot(
f'{proj!r} extent is controlled by "lonlim" and "latlim", '
f"ignoring boundinglat={boundinglat!r}."
)
if any(_ is not None for _ in (*lonlim, *latlim)):
lonlim = list(lonlim)
if lonlim[0] is None:
lonlim[0] = lon0 - 180
if lonlim[1] is None:
lonlim[1] = lon0 + 180
latlim = list(latlim)
if latlim[0] is None:
latlim[0] = -90
if latlim[1] is None:
latlim[1] = 90
extent = lonlim + latlim
self.set_extent(extent, crs=ccrs.PlateCarree())
def _update_features(self) -> None:
"""
Update geographic features.
"""
# NOTE: The e.g. cfeature.COASTLINE features are just for convenience,
# lo res versions. Use NaturalEarthFeature instead.
# WARNING: Seems cartopy features cannot be updated! Updating _kwargs
# attribute does *nothing*.
reso = rc["reso"] # resolution cannot be changed after feature created
try:
reso = constructor.RESOS_CARTOPY[reso]
except KeyError:
raise ValueError(
f"Invalid resolution {reso!r}. Options are: "
+ ", ".join(map(repr, constructor.RESOS_CARTOPY))
+ "."
)
for name, args in constructor.FEATURES_CARTOPY.items():
# Draw feature or toggle feature off
b = rc.find(name, context=True)
attr = f"_{name}_feature"
feat = getattr(self, attr, None)
drawn = feat is not None # if exists, apply *updated* settings
if b is not None:
if not b:
if drawn: # toggle existing feature off
feat.set_visible(False)
else:
if not drawn:
feat = cfeature.NaturalEarthFeature(*args, reso)
feat = self.add_feature(feat) # convert to FeatureArtist
setattr(self, attr, feat)
# Update artist attributes (FeatureArtist._kwargs used back to v0.5).
# For 'lines', need to specify edgecolor and facecolor
# See: https://github.com/SciTools/cartopy/issues/803
if feat is not None:
kw = rc.category(name, context=drawn)
if name in ("coast", "rivers", "borders", "innerborders"):
if "color" in kw:
kw.update({"edgecolor": kw.pop("color"), "facecolor": "none"})
else:
kw.update({"linewidth": 0})
if "zorder" in kw:
# NOTE: Necessary to update zorder directly because _kwargs
# attributes are not applied until draw()... at which point
# matplotlib is drawing in the order based on the *old* zorder.
feat.set_zorder(kw["zorder"])
if hasattr(feat, "_kwargs"):
feat._kwargs.update(kw)
if _version_cartopy >= "0.23":
feat.set(**feat._kwargs)
def _update_gridlines(
self,
gl: _CartopyGridlinerProtocol,
which: str = "major",
longrid: bool | None = None,
latgrid: bool | None = None,
nsteps: int | None = None,
) -> None:
"""
Update gridliner object with axis locators, and toggle gridlines on and off.
"""
# Update gridliner collection properties
# WARNING: Here we use native matplotlib 'grid' rc param for geographic
# gridlines. If rc mode is 1 (first format call) use context=False
kwlines = rc._get_gridline_props(which=which, native=False)
kwtext = rc._get_ticklabel_props(native=False)
gl.collection_kwargs.update(kwlines)
gl.xlabel_style.update(kwtext)
gl.ylabel_style.update(kwtext)
# Apply tick locations from dummy _LonAxis and _LatAxis axes
# NOTE: This will re-apply existing gridline locations if unchanged.
if nsteps is not None:
gl.n_steps = nsteps
# Set xlim and ylim for cartopy >= 0.19 to control which labels are displayed
# NOTE: Don't set xlim/ylim here - let cartopy determine from the axes extent
longrid = rc._get_gridline_bool(longrid, axis="x", which=which, native=False)
if longrid is not None:
gl.xlines = longrid
latgrid = rc._get_gridline_bool(latgrid, axis="y", which=which, native=False)
if latgrid is not None:
gl.ylines = latgrid
lonlines = self._get_lonticklocs(which=which)
latlines = self._get_latticklocs(which=which)
if _version_cartopy >= "0.18": # see lukelbd/ultraplot#208
lonlines = np.asarray(lonlines)
lonlines_mod = (lonlines + 180) % 360 - 180 # only for cartopy
# Preserve distinct -180/180 ticks so both map edges can be labeled.
eps = 1e-10
lonlines_mod = np.where(
np.isclose(lonlines, -180), -180 + eps, lonlines_mod
)
lonlines_mod = np.where(np.isclose(lonlines, 180), 180 - eps, lonlines_mod)
lonlines = lonlines_mod
gl.xlocator = mticker.FixedLocator(lonlines)
gl.ylocator = mticker.FixedLocator(latlines)
self.stale = True
def _update_major_gridlines(
self,
longrid: bool | None = None,
latgrid: bool | None = None,
lonarray: Sequence[bool | None] | None = None,
latarray: Sequence[bool | None] | None = None,
loninline: bool | None = None,
latinline: bool | None = None,
labelpad: Any = None,
rotatelabels: bool | None = None,
lonlabelrotation: float | None = None,
latlabelrotation: float | None = None,
nsteps: int | None = None,
) -> None:
"""
Update major gridlines.
"""
# Update gridline locations and style
gl = self._gridlines_major
if gl is None:
gl = self._gridlines_major = self._init_gridlines()
self._update_gridlines(
gl,
which="major",
longrid=longrid,
latgrid=latgrid,
nsteps=nsteps,
)
gl.xformatter = self._lonaxis.get_major_formatter()
gl.yformatter = self._lataxis.get_major_formatter()
# Turn the tick labels off as they are handled
# separately from the matplotlib defaults
self.xaxis.set_major_formatter(mticker.NullFormatter())
self.yaxis.set_major_formatter(mticker.NullFormatter())
# Update gridline label parameters
# NOTE: Cartopy 0.18 and 0.19 can not draw both edge and inline labels. Instead
# requires both a set 'side' and 'x_inline' is True (applied in GeoAxes.format).
# NOTE: The 'xpadding' and 'ypadding' props were introduced in v0.16
# with default 5 points, then set to default None in v0.18.
# TODO: Cartopy has had two formatters for a while but we use the newer one.
# See https://github.com/SciTools/cartopy/pull/1066
if labelpad is not None:
gl.xpadding = labelpad
gl.ypadding = labelpad
if loninline is not None:
gl.x_inline = bool(loninline)
if latinline is not None:
gl.y_inline = bool(latinline)
if rotatelabels is not None:
gl.rotate_labels = bool(rotatelabels) # ignored in cartopy < 0.18
if lonlabelrotation is not None:
gl.xlabel_style["rotation"] = lonlabelrotation
if latlabelrotation is not None:
gl.ylabel_style["rotation"] = latlabelrotation
if latinline is not None or loninline is not None:
lon, lat = loninline, latinline
b = True if lon and lat else "x" if lon else "y" if lat else None
gl.inline_labels = b # ignored in cartopy < 0.20
# Gridline label toggling
# Issue warning instead of error!
if _version_cartopy < "0.18" and not isinstance(
self.projection, (ccrs.Mercator, ccrs.PlateCarree)
):
if any(latarray):
warnings._warn_ultraplot(
"Cannot add gridline labels to cartopy "
f"{type(self.projection).__name__} projection."
)
latarray = [False] * 5
if any(lonarray):
warnings._warn_ultraplot(
"Cannot add gridline labels to cartopy "
f"{type(self.projection).__name__} projection."
)
lonarray = [False] * 5
# The ordering of these sides are important. The arrays are ordered lrbtg.
sides = _gridliner_sides_from_arrays(
lonarray,
latarray,
order=_CARTOPY_LABEL_SIDES,
allow_xy=True,
include_false=True,
)
if not sides and lonarray is not None and latarray is not None:
# Preserve legacy behavior by calling the toggle even for no-op arrays.
sides = {side: None for side in _CARTOPY_LABEL_SIDES}
if sides:
self._toggle_gridliner_labels(**sides)
self._set_gridliner_adapter("major", self._build_gridliner_adapter("major"))
def _update_minor_gridlines(
self,
longrid: bool | None = None,
latgrid: bool | None = None,
nsteps: int | None = None,
) -> None:
"""
Update minor gridlines.
"""
gl = self._gridlines_minor
if gl is None:
gl = self._gridlines_minor = self._init_gridlines()
self._update_gridlines(
gl,
which="minor",
longrid=longrid,
latgrid=latgrid,
nsteps=nsteps,
)
self._set_gridliner_adapter("minor", self._build_gridliner_adapter("minor"))
def get_extent(self, crs: Any = None) -> Sequence[float]:
# Get extent and try to repair longitude bounds.
if crs is None:
crs = ccrs.PlateCarree()
extent = super().get_extent(crs=crs)
if isinstance(crs, ccrs.PlateCarree):
if np.isclose(extent[0], -180) and np.isclose(extent[-1], 180):
# Repair longitude bounds to reflect dateline position
# NOTE: This is critical so we can prevent duplicate gridlines
# on dateline. See _update_gridlines.
lon0 = self._get_lon0()
extent[:2] = [lon0 - 180, lon0 + 180]
return extent
@override
def draw(self, renderer: Any = None, *args: Any, **kwargs: Any) -> None:
"""
Override draw to adjust panel positions for cartopy axes.
Cartopy's apply_aspect() can shrink the main axes to enforce the projection
aspect ratio. Panels occupy separate gridspec slots, so we reposition them
after the main axes has applied its aspect but before the panel axes are drawn.
"""
super().draw(renderer, *args, **kwargs)
self._adjust_panel_positions(tol=self._PANEL_TOL)
def get_tightbbox(self, renderer: Any, *args: Any, **kwargs: Any) -> Any:
# Perform extra post-processing steps
# For now this just draws the gridliners
self._apply_axis_sharing()
if self.get_autoscale_on() and self.ignore_existing_data_limits:
self.autoscale_view()
# Adjust location
if _version_cartopy >= "0.18":
self.patch._adjust_location() # this does the below steps
elif getattr(self.background_patch, "reclip", None) and hasattr(
self.background_patch, "orig_path"
):
clipped_path = self.background_patch.orig_path.clip_to_bbox(self.viewLim)
self.outline_patch._path = clipped_path
self.background_patch._path = clipped_path
# Apply aspect, then ensure panels follow the aspect-constrained box.
self._apply_aspect_and_adjust_panels(tol=self._PANEL_TOL)
if _version_cartopy >= "0.23":
gridliners = [
a for a in self.artists if isinstance(a, cgridliner.Gridliner)
]
else:
gridliners = self._gridliners
for gl in gridliners:
if _version_cartopy >= "0.18":
gl._draw_gridliner(renderer=renderer)
else:
gl._draw_gridliner(background_patch=self.background_patch)
# Remove gridliners
if _version_cartopy < "0.18":
self._gridliners = []
return super().get_tightbbox(renderer, *args, **kwargs)
def set_extent(self, extent: Sequence[float], crs: Any = None) -> Any:
# Fix paths, so axes tight bounding box gets correct box! From this issue:
# https://github.com/SciTools/cartopy/issues/1207#issuecomment-439975083
# Also record the requested longitude latitude extent so we can use these
# values for LongitudeLocator and LatitudeLocator. Otherwise if longitude
# extent is across dateline LongitudeLocator fails because get_extent()
# reports -180 to 180: https://github.com/SciTools/cartopy/issues/1564
# NOTE: This is *also* not perfect because if set_extent() was called
# and extent crosses map boundary of rectangular projection, the *actual*
# resulting extent is the opposite. But that means user has messed up anyway
# so probably doesn't matter if gridlines are also wrong.
if crs is None:
crs = ccrs.PlateCarree()
if isinstance(crs, ccrs.PlateCarree):
self._set_view_intervals(extent)
with rc.context(mode=2): # do not reset gridline properties!
if self._gridlines_major is not None:
self._update_gridlines(self._gridlines_major, which="major")
if self._gridlines_minor is not None:
self._update_gridlines(self._gridlines_minor, which="minor")
if _version_cartopy < "0.18":
clipped_path = self.outline_patch.orig_path.clip_to_bbox(self.viewLim)
self.outline_patch._path = clipped_path
self.background_patch._path = clipped_path
return super().set_extent(extent, crs=crs)
def set_global(self) -> Any:
# Set up "global" extent and update _LatAxis and _LonAxis view intervals
result = super().set_global()
self._set_view_intervals(self._get_global_extent())
return result
class _BasemapAxes(GeoAxes):
"""
Axes subclass for plotting basemap projections.
"""
_name = "basemap"
_proj_class = Basemap
_proj_north = ("npaeqd", "nplaea", "npstere")
_proj_south = ("spaeqd", "splaea", "spstere")
_proj_polar = _proj_north + _proj_south
_proj_non_rectangular = _proj_polar + ( # do not use axes spines as boundaries
"ortho",
"geos",
"nsper",
"moll",
"hammer",
"robin",
"eck4",
"kav7",
"mbtfpq",
"sinu",
"vandg",
)
_PANEL_TOL = 1e-6
def __init__(self, *args: Any, map_projection: Any = None, **kwargs: Any) -> None:
"""
Parameters
----------
map_projection : ~mpl_toolkits.basemap.Basemap
The map projection.
*args, **kwargs
Passed to `GeoAxes`.
"""
# First assign projection and set axis bounds for locators
# WARNING: Unlike cartopy projections basemaps cannot normally be reused.
# To make syntax similar we make a copy.
# WARNING: Investigated whether Basemap.__init__() could be called
# twice with updated proj kwargs to modify map bounds after creation
# and python immmediately crashes. Do not try again.
import mpl_toolkits.basemap # noqa: F401 verify package is available
self.projection = copy.copy(map_projection) # verify
lon0 = self._get_lon0()
if self.projection.projection in self._proj_polar:
latmax = 80 # default latmax for gridlines
extent = [-180 + lon0, 180 + lon0]
bound = getattr(self.projection, "boundinglat", 0)
north = self.projection.projection in self._proj_north
extent.extend([bound, 90] if north else [-90, bound])
else:
latmax = 90
attrs = ("lonmin", "lonmax", "latmin", "latmax")
extent = [getattr(self.projection, attr, None) for attr in attrs]
if any(_ is None for _ in extent):
extent = [180 - lon0, 180 + lon0, -90, 90] # fallback
# Initialize axes
self._map_boundary = None # see format()
self._has_recurred = False # use this to override plotting methods
self._lonlines_major = None # store gridliner objects this way
self._lonlines_minor = None
self._latlines_major = None
self._latlines_minor = None
self._lonarray = 4 * [False] # cached label toggles
self._latarray = 4 * [False] # cached label toggles
self._lonaxis = _LonAxis(self)
self._lataxis = _LatAxis(self, latmax=latmax)
self._set_view_intervals(extent)
super().__init__(*args, **kwargs)
self._turnoff_tick_labels(self._lonlines_major)
self._turnoff_tick_labels(self._latlines_major)
def get_tightbbox(self, renderer: Any, *args: Any, **kwargs: Any) -> Any:
"""
Get tight bounding box, adjusting panel positions after aspect is applied.
This ensures panels are properly aligned when saving figures, as apply_aspect()
may be called during the rendering process.
"""
# Apply aspect ratio, then ensure panels follow the aspect-constrained box.
self._apply_aspect_and_adjust_panels(tol=self._PANEL_TOL)
return super().get_tightbbox(renderer, *args, **kwargs)
@override
def draw(self, renderer: Any = None, *args: Any, **kwargs: Any) -> None:
"""
Override draw to adjust panel positions for basemap axes.
Basemap projections also rely on apply_aspect() and can shrink the main axes;
panels must be repositioned to flank the visible map boundaries.
"""
super().draw(renderer, *args, **kwargs)
self._adjust_panel_positions(tol=self._PANEL_TOL)
def _turnoff_tick_labels(self, locator: GridlineDict) -> None:
"""
For GeoAxes with are dealing with a duality. Basemap axes behave differently than Cartopy axes and vice versa. UltraPlot abstracts away from these by providing GeoAxes. For basemap axes we need to turn off the tick labels as they will be handles by GeoAxis
"""
for loc, objects in locator.items():
for object in objects:
# text is wrapped in a list
if isinstance(object, list) and len(object) > 0:
object = object[0]
if isinstance(object, mtext.Text):
object.set_visible(False)
def _get_lon0(self) -> float:
"""
Get the central longitude.
"""
return getattr(self.projection, "projparams", {}).get("lon_0", 0)
@staticmethod
def _iter_gridlines(dict_: GridlineDict | None) -> Iterator[Any]:
"""
Iterate over longitude latitude lines.
"""
dict_ = dict_ or {}
for pi in dict_.values():
for pj in pi:
for obj in pj:
yield obj
def _build_gridliner_adapter(
self, which: str = "major"
) -> Optional[_GridlinerAdapter]:
lonlines = getattr(self, f"_lonlines_{which}", None)
latlines = getattr(self, f"_latlines_{which}", None)
if lonlines is None or latlines is None:
return None
return _BasemapGridlinerAdapter(lonlines, latlines)
def _update_background(self, **kwargs: Any) -> None:
"""
Update the map boundary patches. This is called in `Axes.format`.
"""
# Non-rectangular projections
# WARNING: Map boundary must be drawn before all other tasks. See __init__.
# WARNING: With clipping on boundary lines are clipped by the axes bbox.
if self.projection.projection in self._proj_non_rectangular:
self.patch.set_facecolor("none") # make sure main patch is hidden
kw_face, kw_edge = rc._get_background_props(native=False, **kwargs)
kw = {**kw_face, **kw_edge, "rasterized": False, "clip_on": False}
self._map_boundary.update(kw)
# Rectangular projections
else:
kw_face, kw_edge = rc._get_background_props(native=False, **kwargs)
self.patch.update({**kw_face, "edgecolor": "none"})
for spine in self.spines.values():
spine.update(kw_edge)
def _update_boundary(self, round: bool | None = None) -> None:
"""
No-op. Boundary mode cannot be changed in basemap.
"""
# NOTE: Unlike the cartopy method we do not look up the rc setting here.
if round is None:
return
else:
warnings._warn_ultraplot(
f"Got round={round!r}, but you cannot change the bounds of a polar "
"basemap projection after creating it. Please pass 'round' to uplt.Proj " # noqa: E501
"instead (e.g. using the uplt.subplots() dictionary keyword 'proj_kw')."
)
def _update_extent_mode(
self, extent: str | None = None, boundinglat: float | None = None
) -> None: # noqa: U100
"""
No-op. Extent mode cannot be changed in basemap.
"""
# NOTE: Unlike the cartopy method we do not look up the rc setting here.
if extent is None:
return
if extent not in ("globe", "auto"):
raise ValueError(
f"Invalid extent mode {extent!r}. Must be 'auto' or 'globe'."
)
if extent == "auto":
warnings._warn_ultraplot(
f"Got extent={extent!r}, but you cannot use auto extent mode "
"in basemap projections. Please consider switching to cartopy."
)
def _update_extent(
self,
lonlim: tuple[float | None, float | None] | None = None,
latlim: tuple[float | None, float | None] | None = None,
boundinglat: float | None = None,
) -> None:
"""
No-op. Map bounds cannot be changed in basemap.
"""
lonlim = _not_none(lonlim, (None, None))
latlim = _not_none(latlim, (None, None))
if boundinglat is not None or any(_ is not None for _ in (*lonlim, *latlim)):
warnings._warn_ultraplot(
f"Got lonlim={lonlim!r}, latlim={latlim!r}, boundinglat={boundinglat!r}"
', but you cannot "zoom into" a basemap projection after creating it. '
"Please pass any of the following keyword arguments to uplt.Proj "
"instead (e.g. using the uplt.subplots() dictionary keyword 'proj_kw'):"
"'boundinglat', 'lonlim', 'latlim', 'llcrnrlon', 'llcrnrlat', "
"'urcrnrlon', 'urcrnrlat', 'llcrnrx', 'llcrnry', 'urcrnrx', 'urcrnry', "
"'width', or 'height'."
)
def _update_features(self) -> None:
"""
Update geographic features.
"""
# NOTE: Also notable are drawcounties, blumarble, drawlsmask,
# shadedrelief, and etopo methods.
for name, method in constructor.FEATURES_BASEMAP.items():
# Draw feature or toggle on and off
b = rc.find(name, context=True)
attr = f"_{name}_feature"
feat = getattr(self, attr, None)
drawn = feat is not None # if exists, apply *updated* settings
if b is not None:
if not b:
if drawn: # toggle existing feature off
for obj in feat:
feat.set_visible(False)
else:
if not drawn:
feat = getattr(self.projection, method)(ax=self)
if not isinstance(feat, (list, tuple)): # list of artists?
feat = (feat,)
setattr(self, attr, feat)
# Update settings
if feat is not None:
kw = rc.category(name, context=drawn)
for obj in feat:
obj.update(kw)
def _update_gridlines(
self,
which: str = "major",
longrid: bool | None = None,
latgrid: bool | None = None,
lonarray: Sequence[bool | None] | None = None,
latarray: Sequence[bool | None] | None = None,
lonlabelrotation: float | None = None,
latlabelrotation: float | None = None,
) -> None:
"""
Apply changes to the basemap axes.
"""
latmax = self._lataxis.get_latmax()
for axis, name, grid, array, method, rotation in zip(
("x", "y"),
("lon", "lat"),
(longrid, latgrid),
(lonarray, latarray),
("drawmeridians", "drawparallels"),
(lonlabelrotation, latlabelrotation),
):
# Correct lonarray and latarray label toggles by changing from lrbt to lrtb.
# Then update the cahced toggle array. This lets us change gridline locs
# while preserving the label toggle setting from a previous format() call.
grid = rc._get_gridline_bool(grid, axis=axis, which=which, native=False)
axis = getattr(self, f"_{name}axis")
if len(array) == 5: # should be always
array = array[:4]
bools = 4 * [False] if which == "major" else getattr(self, f"_{name}array")
array = [*array[:2], *array[2:4][::-1]] # flip lrbt to lrtb and skip geo
for i, b in enumerate(array):
if b is not None:
bools[i] = b # update toggles
# Get gridlines
# NOTE: This may re-apply existing gridlines.
lines = list(getattr(self, f"_get_{name}ticklocs")(which=which))
if name == "lon" and np.isclose(lines[0] + 360, lines[-1]):
lines = lines[:-1] # prevent double labels
# Figure out whether we have to redraw meridians/parallels
# NOTE: Always update minor gridlines if major locator also changed
attr = f"_{name}lines_{which}"
objs = getattr(self, attr) # dictionary of previous objects
attrs = ["isDefault_majloc"] # always check this one
attrs.append("isDefault_majfmt" if which == "major" else "isDefault_minloc")
rebuild = lines and (
not objs
or any(_ is not None for _ in array) # user-input or initial toggles
or any(not getattr(axis, attr) for attr in attrs) # none tracked yet
)
if rebuild and objs and grid is None: # get *previous* toggle state
grid = all(obj.get_visible() for obj in self._iter_gridlines(objs))
# Draw or redraw meridian or parallel lines
# Also mark formatters and locators as 'default'
if rebuild:
kwdraw = {}
formatter = axis.get_major_formatter()
if formatter is not None: # use functional formatter
kwdraw["fmt"] = formatter
for obj in self._iter_gridlines(objs):
obj.set_visible(False)
objs = getattr(self.projection, method)(
lines, ax=self, latmax=latmax, labels=bools, **kwdraw
)
setattr(self, attr, objs)
# Update gridline settings
# We use native matplotlib 'grid' rc param for geographic gridlines
kwlines = rc._get_gridline_props(which=which, native=False, rebuild=rebuild)
kwtext = rc._get_ticklabel_props(native=False, rebuild=rebuild)
for obj in self._iter_gridlines(objs):
if isinstance(obj, mtext.Text):
obj.update(kwtext)
# Apply rotation if specified
if rotation is not None:
obj.set_rotation(rotation)
else:
obj.update(kwlines)
# Toggle existing gridlines on and off
if grid is not None:
for obj in self._iter_gridlines(objs):
if not isinstance(obj, mtext.Text):
obj.set_visible(grid)
def _update_major_gridlines(
self,
longrid: bool | None = None,
latgrid: bool | None = None,
lonarray: Sequence[bool | None] | None = None,
latarray: Sequence[bool | None] | None = None,
loninline: bool | None = None,
latinline: bool | None = None,
rotatelabels: bool | None = None,
lonlabelrotation: float | None = None,
latlabelrotation: float | None = None,
labelpad: Any = None,
nsteps: int | None = None,
) -> None:
"""
Update major gridlines.
"""
loninline, latinline, labelpad, rotatelabels, nsteps # avoid U100 error
self._update_gridlines(
which="major",
longrid=longrid,
latgrid=latgrid,
lonarray=lonarray,
latarray=latarray,
lonlabelrotation=lonlabelrotation,
latlabelrotation=latlabelrotation,
)
sides = _gridliner_sides_from_arrays(
lonarray,
latarray,
order=_BASEMAP_LABEL_SIDES,
allow_xy=False,
include_false=False,
)
if sides:
self._toggle_gridliner_labels(**sides)
self._set_gridliner_adapter("major", self._build_gridliner_adapter("major"))
def _update_minor_gridlines(
self,
longrid: bool | None = None,
latgrid: bool | None = None,
nsteps: int | None = None,
) -> None:
"""
Update minor gridlines.
"""
# Update gridline locations
nsteps # avoid U100 error
array = [None] * 4 # NOTE: must be None not False (see _update_gridlines)
self._update_gridlines(
which="minor",
longrid=longrid,
latgrid=latgrid,
lonarray=array,
latarray=array,
lonlabelrotation=None,
latlabelrotation=None,
)
self._set_gridliner_adapter("minor", self._build_gridliner_adapter("minor"))
# Set isDefault_majloc, etc. to True for both axes
# NOTE: This cannot be done inside _update_gridlines or minor gridlines
# will not update to reflect new major gridline locations.
for axis in (self._lonaxis, self._lataxis):
axis.isDefault_majfmt = True
axis.isDefault_majloc = True
axis.isDefault_minloc = True
def _is_platecarree_crs(transform: Any) -> bool:
"""
Return whether `transform` represents plain longitude-latitude coordinates.
"""
if transform is None:
return True
name = getattr(getattr(transform, "__class__", None), "__name__", "")
return name == "PlateCarree"
def _choropleth_close_path(vertices: Any) -> mpath.Path | None:
"""
Convert a single polygon ring into a closed path.
"""
vertices = np.asarray(vertices, dtype=float)
if vertices.ndim != 2 or vertices.shape[0] < 3:
return None
vertices = vertices[:, :2]
if not np.allclose(vertices[0], vertices[-1], equal_nan=True):
vertices = np.vstack((vertices, vertices[0]))
codes = np.full(vertices.shape[0], mpath.Path.LINETO, dtype=np.uint8)
codes[0] = mpath.Path.MOVETO
codes[-1] = mpath.Path.CLOSEPOLY
return mpath.Path(vertices, codes)
def _choropleth_iter_rings(geometry: Any) -> Iterator[Any]:
"""
Yield polygon rings from shapely-like polygon geometries.
"""
if geometry is None or getattr(geometry, "is_empty", False):
return
geom_type = getattr(geometry, "geom_type", None)
if geom_type == "Polygon":
yield geometry.exterior.coords
for ring in geometry.interiors:
yield ring.coords
return
if geom_type in ("MultiPolygon", "GeometryCollection"):
for part in getattr(geometry, "geoms", ()):
yield from _choropleth_iter_rings(part)
return
raise TypeError(
"choropleth() geometries must be polygon-like shapely objects. "
f"Got {type(geometry).__name__}."
)
def _choropleth_project_vertices(
ax: GeoAxes,
vertices: Any,
*,
transform: Any = None,
) -> np.ndarray:
"""
Project polygon-ring vertices into the target map coordinate system.
"""
vertices = np.asarray(vertices, dtype=float)
xy = vertices[:, :2]
if ax._name == "cartopy":
src = transform
if src is None:
if ccrs is None:
raise RuntimeError("choropleth() requires cartopy for cartopy GeoAxes.")
src = ccrs.PlateCarree()
out = ax.projection.transform_points(src, xy[:, 0], xy[:, 1])
return np.asarray(out[:, :2], dtype=float)
if transform is not None and not _is_platecarree_crs(transform):
raise ValueError(
"Basemap choropleth() only supports longitude-latitude input "
"coordinates. Use transform=None or cartopy.crs.PlateCarree()."
)
x, y = ax.projection(xy[:, 0], xy[:, 1])
return np.column_stack((np.asarray(x, dtype=float), np.asarray(y, dtype=float)))
def _choropleth_geometry_path(
ax: GeoAxes,
geometry: Any,
*,
transform: Any = None,
) -> mpath.Path | None:
"""
Convert a polygon geometry to a projected matplotlib path.
"""
if ax._name == "cartopy":
src = transform
if src is None:
if ccrs is None:
raise RuntimeError("choropleth() requires cartopy for cartopy GeoAxes.")
src = ccrs.PlateCarree()
projected_geom = ax.projection.project_geometry(geometry, src)
paths = []
for ring in _choropleth_iter_rings(projected_geom):
path = _choropleth_close_path(np.asarray(ring, dtype=float))
if path is not None:
paths.append(path)
if not paths:
return None
return mpath.Path.make_compound_path(*paths)
paths = []
for ring in _choropleth_iter_rings(geometry):
projected = _choropleth_project_vertices(ax, ring, transform=transform)
path = _choropleth_close_path(projected)
if path is not None:
paths.append(path)
if not paths:
return None
return mpath.Path.make_compound_path(*paths)
def _choropleth_country_inputs(
geometries: Any,
values: Any,
*,
transform: Any = None,
resolution: str = "110m",
include_far: bool = False,
) -> tuple[list[Any], Any, Any]:
"""
Resolve country identifiers into polygon geometries.
"""
from .. import legend as plegend
if values is None:
if not isinstance(geometries, Mapping):
raise ValueError(
"choropleth(country=True) requires either values=... or a "
"mapping of country identifiers to numeric values."
)
keys = list(geometries.keys())
values = list(geometries.values())
else:
if isinstance(geometries, Mapping):
raise ValueError(
"choropleth(country=True) does not accept both a mapping input "
"and an explicit values=... argument."
)
keys = list(geometries)
if transform is not None and not _is_platecarree_crs(transform):
raise ValueError(
"choropleth(country=True) uses Natural Earth lon/lat geometries, so "
"transform must be None or cartopy.crs.PlateCarree()."
)
resolution = plegend._normalize_country_resolution(resolution)
geometries = [
plegend._resolve_country_geometry(
str(key),
resolution=resolution,
include_far=include_far,
)
for key in keys
]
return geometries, values, transform
def _choropleth_edge_collection_kw(
kw: Mapping[str, Any],
*,
zorder: float,
explicit_zorder: bool = False,
) -> dict[str, Any] | None:
"""
Return edge-only collection settings when polygon outlines should overlay features.
"""
edge_keys = (
"edgecolor",
"edgecolors",
"linewidth",
"linewidths",
"linestyle",
"linestyles",
)
if not any(key in kw for key in edge_keys):
return None
edge_kw = {
key: value
for key, value in kw.items()
if key not in ("color", "colors", "facecolor", "facecolors", "hatch", "label")
}
if explicit_zorder:
edge_kw["zorder"] = zorder
else:
edge_kw["zorder"] = (
max(
zorder,
*(
rc.find(f"{name}.zorder", context=True)
for name in ("coast", "rivers", "borders", "innerborders")
),
)
+ 0.1
)
edge_kw["facecolor"] = "none"
return edge_kw
# Apply signature obfuscation after storing previous signature
GeoAxes._format_signatures[GeoAxes] = inspect.signature(GeoAxes.format)
GeoAxes.format = docstring._obfuscate_kwargs(GeoAxes.format)
def _is_rectilinear_projection(ax: Any) -> bool:
"""Check if the axis has a flat projection (works with Cartopy)."""
rectilinear_basemap = {
"cyl",
"merc",
"mill",
"rect",
"rectilinear",
"unknown",
}
# Determine what the projection function is
# Create a square and determine if the lengths are preserved
# For geoaxes projc is always set in format, and thus is not None
proj = getattr(ax, "projection", None)
# Prefer explicit projection identifiers for known cylindrical projections.
# Numerical transform checks can be slightly lossy for cartopy projections
# like PlateCarree, which incorrectly makes a rectilinear projection look
# curved due to floating point noise in projected coordinates.
if ccrs is not None and isinstance(proj, ccrs.Projection):
rectilinear_cartopy = (
ccrs.PlateCarree,
ccrs.Mercator,
ccrs.LambertCylindrical,
ccrs.Miller,
)
return isinstance(proj, rectilinear_cartopy)
if hasattr(proj, "projection") and proj.projection is not None:
return proj.projection.lower() in rectilinear_basemap
transform = None
if hasattr(proj, "transform_point"): # cartopy
if proj.transform_point is not None:
transform = partial(proj.transform_point, src_crs=proj.as_geodetic())
elif hasattr(proj, "projection"): # basemap
transform = proj
if transform is not None:
# Create three collinear points (in a straight line)
line_points = [(0, 0), (10, 10), (20, 20)]
# Transform the points using the projection
transformed_points = [transform(x, y) for x, y in line_points]
# Check if the transformed points are still collinear
# Points are collinear if the slopes between consecutive points are equal
x0, y0 = transformed_points[0]
x1, y1 = transformed_points[1]
x2, y2 = transformed_points[2]
# Calculate slopes
xdiff1 = x1 - x0
xdiff2 = x2 - x1
if np.allclose(xdiff1, 0) or np.allclose(xdiff2, 0): # Avoid division by zero
# Check if both are vertical lines
return np.allclose(xdiff1, 0) and np.allclose(xdiff2, 0)
slope1 = (y1 - y0) / xdiff1
slope2 = (y2 - y1) / xdiff2
# If slopes are equal (within a small tolerance), the projection preserves straight lines
return np.allclose(slope1 - slope2, 0)
# If we can't determine, assume it's not rectilinear
return False
