DEP: drop support for matplotlib<3.5

pyproject.toml

@@ -48,7 +48,7 @@ dependencies = [
     "cmyt>=1.1.2",
     "ewah-bool-utils>=1.0.2",
     "ipywidgets>=8.0.0",
-    "matplotlib!=3.4.2,>=3.2", # keep in sync with tests/windows_conda_requirements.txt
+    "matplotlib>=3.5", # keep in sync with tests/windows_conda_requirements.txt
     "more-itertools>=8.4",
     "numpy>=1.17.5",
     "packaging>=20.9",
@@ -208,7 +208,7 @@ minimal = [
     "cmyt==1.1.2",
     "ewah-bool-utils==1.0.2",
     "ipywidgets==8.0.0",
-    "matplotlib==3.2",
+    "matplotlib==3.5",
     "more-itertools==8.4",
     "numpy==1.17.5",
     "packaging==20.9",

tests/windows_conda_requirements.txt

@@ -1,5 +1,5 @@
 numpy>=1.19.4
 cartopy>=0.21.0
 h5py>=3.1.0
-matplotlib!=3.4.2,>=3.2  # keep in sync with pyproject.toml
+matplotlib>=3.5  # keep in sync with pyproject.toml
 scipy>=1.5.0

yt/funcs.py

@@ -22,7 +22,6 @@
 
 import numpy as np
 from more_itertools import always_iterable, collapse, first
-from packaging.version import Version
 
 from yt._maintenance.deprecation import issue_deprecation_warning
 from yt.config import ytcfg
@@ -1002,11 +1001,10 @@ def matplotlib_style_context(style="yt.default", after_reset=False):
     """
     # FUTURE: this function should be deprecated in favour of matplotlib.style.context
     # after support for matplotlib 3.6 and older versions is dropped.
+    import matplotlib as mpl
     import matplotlib.style
 
-    from yt.visualization._commons import MPL_VERSION
-
-    if style == "yt.default" and MPL_VERSION < Version("3.7"):
+    if style == "yt.default" and mpl.__version_info__ < (3, 7):
         style = importlib_resources.files("yt") / "default.mplstyle"
 
     return matplotlib.style.context(style, after_reset=after_reset)

yt/visualization/_commons.py

@@ -2,14 +2,11 @@
 import sys
 import warnings
 from functools import wraps
-from importlib.metadata import version
 from typing import TYPE_CHECKING, Optional, Type, TypeVar
 
 import matplotlib as mpl
-import numpy as np
 from matplotlib.ticker import SymmetricalLogLocator
 from more_itertools import always_iterable
-from packaging.version import Version
 
 from yt.config import ytcfg
 
@@ -27,15 +24,13 @@
     from matplotlib.backend_bases import FigureCanvasBase
 
 
-MPL_VERSION = Version(version("matplotlib"))
-
 _yt_style = mpl.rc_params_from_file(
     importlib_resources.files("yt") / "default.mplstyle", use_default_template=False
 )
-DEFAULT_FONT_PROPERTIES = {"family": _yt_style["font.family"][0]}
-
-if MPL_VERSION >= Version("3.4"):
-    DEFAULT_FONT_PROPERTIES["math_fontfamily"] = _yt_style["mathtext.fontset"]
+DEFAULT_FONT_PROPERTIES = {
+    "family": _yt_style["font.family"][0],
+    "math_fontfamily": _yt_style["mathtext.fontset"],
+}
 del _yt_style
 
 
@@ -228,78 +223,12 @@ def _swap_arg_pair_order(*args):
     return tuple(new_args)
 
 
-def get_symlog_majorticks(linthresh: float, vmin: float, vmax: float) -> np.ndarray:
-    """calculate positions of major ticks on a log colorbar
-
-    Parameters
-    ----------
-    linthresh : float
-        the threshold for the linear region
-    vmin : float
-        the minimum value in the colorbar
-    vmax : float
-        the maximum value in the colorbar
-
-    """
-    if MPL_VERSION >= Version("3.5"):
-        raise RuntimeError("get_symlog_majorticks is not needed with matplotlib>=3.5")
-
-    if vmin >= 0.0:
-        yticks = [vmin] + list(
-            10
-            ** np.arange(
-                np.rint(np.log10(linthresh)),
-                np.ceil(np.log10(1.1 * vmax)),
-            )
-        )
-    elif vmax <= 0.0:
-        if MPL_VERSION >= Version("3.5.0b"):
-            offset = 0
-        else:
-            offset = 1
-
-        yticks = list(
-            -(
-                10
-                ** np.arange(
-                    np.floor(np.log10(-vmin)),
-                    np.rint(np.log10(linthresh)) - offset,
-                    -1,
-                )
-            )
-        ) + [vmax]
-    else:
-        yticks = (
-            list(
-                -(
-                    10
-                    ** np.arange(
-                        np.floor(np.log10(-vmin)),
-                        np.rint(np.log10(linthresh)) - 1,
-                        -1,
-                    )
-                )
-            )
-            + [0]
-            + list(
-                10
-                ** np.arange(
-                    np.rint(np.log10(linthresh)),
-                    np.ceil(np.log10(1.1 * vmax)),
-                )
-            )
-        )
-    if yticks[-1] > vmax:
-        yticks.pop()
-    return np.array(yticks)
-
-
 class _MPL38_SymmetricalLogLocator(SymmetricalLogLocator):
     # Backporting behaviour from matplotlib 3.8 (in development at the time of writing)
     # see https://github.com/matplotlib/matplotlib/pull/25970
 
     def __init__(self, *args, **kwargs):
-        if MPL_VERSION >= Version("3.8"):
+        if mpl.__version_info__ >= (3, 8):
             raise RuntimeError(
                 "_MPL38_SymmetricalLogLocator is not needed with matplotlib>=3.8"
             )

yt/visualization/_handlers.py

@@ -2,6 +2,7 @@
 from numbers import Real
 from typing import Any, Dict, List, Literal, Optional, Tuple, Type, Union
 
+import matplotlib as mpl
 import numpy as np
 import unyt as un
 from matplotlib.colors import Colormap, LogNorm, Normalize, SymLogNorm
@@ -10,7 +11,6 @@
 from yt._typing import Quantity, Unit
 from yt.config import ytcfg
 from yt.funcs import get_brewer_cmap, is_sequence, mylog
-from yt.visualization.color_maps import _get_cmap
 
 
 class NormHandler:
@@ -438,14 +438,14 @@ def draw_minorticks(self, newval) -> None:
 
     @property
     def cmap(self) -> Colormap:
-        return self._cmap or _get_cmap(ytcfg.get("yt", "default_colormap"))
+        return self._cmap or mpl.colormaps[ytcfg.get("yt", "default_colormap")]
 
     @cmap.setter
     def cmap(self, newval) -> None:
         if isinstance(newval, Colormap) or newval is None:
             self._cmap = newval
         elif isinstance(newval, str):
-            self._cmap = _get_cmap(newval)
+            self._cmap = mpl.colormaps[newval]
         elif is_sequence(newval):
             # tuple colormaps are from palettable (or brewer2mpl)
             self._cmap = get_brewer_cmap(newval)

yt/visualization/base_plot_types.py

@@ -6,21 +6,17 @@
 
 import matplotlib
 import numpy as np
-from matplotlib.colors import LogNorm, Normalize, SymLogNorm
 from matplotlib.ticker import LogFormatterMathtext
-from packaging.version import Version
 
 from yt.funcs import get_interactivity, is_sequence, matplotlib_style_context, mylog
 from yt.visualization._handlers import ColorbarHandler, NormHandler
 
 from ._commons import (
-    MPL_VERSION,
     get_canvas,
-    get_symlog_majorticks,
     validate_image_name,
 )
 
-if MPL_VERSION >= Version("3.8"):
+if matplotlib.__version_info__ >= (3, 8):
     from matplotlib.ticker import SymmetricalLogLocator
 else:
     from ._commons import _MPL38_SymmetricalLogLocator as SymmetricalLogLocator
@@ -164,8 +160,6 @@ def save(self, name, mpl_kwargs=None, canvas=None):
 
         if mpl_kwargs is None:
             mpl_kwargs = {}
-        if "papertype" not in mpl_kwargs and MPL_VERSION < Version("3.3.0"):
-            mpl_kwargs["papertype"] = "auto"
 
         name = validate_image_name(name)
 
@@ -312,56 +306,9 @@ def _init_image(self, data, extent, aspect):
             interpolation="nearest",
             transform=transform,
         )
-        self._set_axes(norm)
+        self._set_axes()
 
-    def _set_axes(self, norm: Normalize) -> None:
-        if MPL_VERSION >= Version("3.5"):
-            self._set_axes_mpl_ge35()
-        else:
-            self._set_axes_mpl_lt35(norm)
-
-    def _set_axes_mpl_lt35(self, norm: Normalize) -> None:
-        # bug-for-bug backward-compatibility for matplotlib older than 3.5
-        if isinstance(norm, SymLogNorm):
-            formatter = LogFormatterMathtext(linthresh=norm.linthresh)
-            self.cb = self.figure.colorbar(self.image, self.cax, format=formatter)
-            self.cb.set_ticks(
-                get_symlog_majorticks(
-                    linthresh=norm.linthresh, vmin=norm.vmin, vmax=norm.vmax
-                )
-            )
-        else:
-            self.cb = self.figure.colorbar(self.image, self.cax)
-        self.cax.tick_params(which="both", axis="y", direction="in")
-
-        fmt_kwargs = {"style": "scientific", "scilimits": (-2, 3), "useMathText": True}
-        self.image.axes.ticklabel_format(**fmt_kwargs)
-        if type(norm) not in (LogNorm, SymLogNorm):
-            try:
-                self.cb.ax.ticklabel_format(**fmt_kwargs)
-            except AttributeError:
-                warnings.warn(
-                    "Failed to format colorbar ticks. "
-                    "This is expected when using the set_norm method "
-                    "with some matplotlib classes (e.g. TwoSlopeNorm) "
-                    "with matplotlib versions older than 3.5\n"
-                    "Please try upgrading matplotlib to a more recent version. "
-                    "If the problem persists, please file a report to "
-                    "https://github.com/yt-project/yt/issues/new",
-                    stacklevel=2,
-                )
-
-        if self.colorbar_handler.draw_minorticks:
-            if not isinstance(norm, SymLogNorm):
-                # no known working method to draw symlog minor ticks
-                # see https://github.com/yt-project/yt/issues/3535
-                self.cax.minorticks_on()
-        else:
-            self.cax.minorticks_off()
-
-        self.image.axes.set_facecolor(self.colorbar_handler.background_color)
-
-    def _set_axes_mpl_ge35(self) -> None:
+    def _set_axes(self) -> None:
         fmt_kwargs = {"style": "scientific", "scilimits": (-2, 3), "useMathText": True}
         self.image.axes.ticklabel_format(**fmt_kwargs)
         self.image.axes.set_facecolor(self.colorbar_handler.background_color)

yt/visualization/color_maps.py

@@ -1,35 +1,14 @@
-from copy import deepcopy
-from typing import Optional, Tuple, Union
+from typing import Tuple, Union
 
 import cmyt  # noqa: F401
 import matplotlib as mpl
 import numpy as np
-from matplotlib.colors import Colormap, LinearSegmentedColormap
-from packaging.version import Version
+from matplotlib.colors import LinearSegmentedColormap
 
 from yt.funcs import get_brewer_cmap
 from yt.utilities.logger import ytLogger as mylog
 
 from . import _colormap_data as _cm
-from ._commons import MPL_VERSION
-
-
-# wrap matplotlib.cm API, use non-deprecated API when available
-def _get_cmap(name: str) -> Colormap:
-    if MPL_VERSION >= Version("3.5"):
-        return mpl.colormaps[name]
-    else:
-        # deprecated API
-        return mpl.cm.get_cmap(name)
-
-
-def _register_cmap(cmap: Colormap, *, name: Optional[str] = None) -> None:
-    if MPL_VERSION >= Version("3.5"):
-        mpl.colormaps.register(cmap, name=name)
-    else:
-        # deprecated API
-        mpl.cm.register_cmap(name=name, cmap=cmap)
-
 
 yt_colormaps = {}
 
@@ -40,7 +19,7 @@ def add_colormap(name, cdict):
     """
     # Note: this function modifies the global variable 'yt_colormaps'
     yt_colormaps[name] = LinearSegmentedColormap(name, cdict, 256)
-    _register_cmap(yt_colormaps[name], name=name)
+    mpl.colormaps.register(yt_colormaps[name])
 
 
 # YTEP-0040 backward compatibility layer
@@ -69,18 +48,10 @@ def register_yt_colormaps_from_cmyt():
     """
 
     for hist_name, alias in _HISTORICAL_ALIASES.items():
-        if MPL_VERSION >= Version("3.4.0"):
-            cmap = _get_cmap(alias).copy()
-        else:
-            cmap = deepcopy(_get_cmap(alias))
+        cmap = mpl.colormaps[alias].copy()
         cmap.name = hist_name
-        try:
-            _register_cmap(cmap=cmap)
-            _register_cmap(cmap=_get_cmap(hist_name).reversed())
-        except ValueError:
-            # Matplotlib 3.4.0 hard-forbids name collisions, but more recent versions
-            # will emit a warning instead, so we emulate this behaviour regardless.
-            mylog.warning("cannot register colormap '%s' (naming collision)", hist_name)
+        mpl.colormaps.register(cmap)
+        mpl.colormaps.register(cmap.reversed())
 
 
 register_yt_colormaps_from_cmyt()
@@ -114,7 +85,7 @@ def get_colormap_lut(cmap_id: Union[Tuple[str, str], str]):
     if isinstance(cmap_id, tuple) and len(cmap_id) == 2:
         cmap = get_brewer_cmap(cmap_id)
     elif isinstance(cmap_id, str):
-        cmap = _get_cmap(cmap_id)
+        cmap = mpl.colormaps[cmap_id]
     else:
         raise TypeError(
             "Expected a string or a 2-tuple of strings as a colormap id. "
@@ -201,7 +172,7 @@ def show_colormaps(subset="all", filename=None):
     for i, m in enumerate(maps):
         plt.subplot(1, l, i + 1)
         plt.axis("off")
-        plt.imshow(a, aspect="auto", cmap=_get_cmap(m), origin="lower")
+        plt.imshow(a, aspect="auto", cmap=mpl.colormaps[m], origin="lower")
         plt.title(m, rotation=90, fontsize=10, verticalalignment="bottom")
     if filename is not None:
         plt.savefig(filename, dpi=100, facecolor="gray")

yt/visualization/profile_plotter.py

@@ -1555,6 +1555,6 @@ def _init_image(
             shading=self._shading,
         )
 
-        self._set_axes(norm)
+        self._set_axes()
         self.axes.set_xscale(x_scale)
         self.axes.set_yscale(y_scale)