feat: axes class and kwargs for twinx and twiny

Author: cmp0xff

lib/matplotlib/axes/_base.py

@@ -4596,7 +4596,7 @@ def _make_twin_axes(self, *args, **kwargs):
         self._twinned_axes.join(self, twin)
         return twin
 
-    def twinx(self):
+    def twinx(self, **kwargs):
         """
         Create a twin Axes sharing the xaxis.
 
@@ -4606,6 +4606,11 @@ def twinx(self):
         Axes.  To ensure that the tick marks of both y-axes align, see
         `~matplotlib.ticker.LinearLocator`.
 
+        Parameters
+        ----------
+        kwargs : dict
+            The keyword arguments passed to ``add_subplot()`` or ``add_axes()``.
+
         Returns
         -------
         Axes
@@ -4616,7 +4621,7 @@ def twinx(self):
         For those who are 'picking' artists while using twinx, pick
         events are only called for the artists in the top-most Axes.
         """
-        ax2 = self._make_twin_axes(sharex=self)
+        ax2 = self._make_twin_axes(sharex=self, axes_class=type(self), **kwargs)
         ax2.yaxis.tick_right()
         ax2.yaxis.set_label_position('right')
         ax2.yaxis.set_offset_position('right')
@@ -4627,7 +4632,7 @@ def twinx(self):
         ax2.xaxis.units = self.xaxis.units
         return ax2
 
-    def twiny(self):
+    def twiny(self, **kwargs):
         """
         Create a twin Axes sharing the yaxis.
 
@@ -4637,6 +4642,11 @@ def twiny(self):
         To ensure that the tick marks of both x-axes align, see
         `~matplotlib.ticker.LinearLocator`.
 
+        Parameters
+        ----------
+        kwargs : dict
+            The keyword arguments passed to ``add_subplot()`` or ``add_axes()``.
+
         Returns
         -------
         Axes
@@ -4647,7 +4657,7 @@ def twiny(self):
         For those who are 'picking' artists while using twiny, pick
         events are only called for the artists in the top-most Axes.
         """
-        ax2 = self._make_twin_axes(sharey=self)
+        ax2 = self._make_twin_axes(sharey=self, axes_class=type(self), **kwargs)
         ax2.xaxis.tick_top()
         ax2.xaxis.set_label_position('top')
         ax2.set_autoscaley_on(self.get_autoscaley_on())

lib/matplotlib/axes/_base.pyi

@@ -4,7 +4,6 @@ import datetime
 from collections.abc import Callable, Iterable, Iterator, Sequence
 from matplotlib import cbook
 from matplotlib.artist import Artist
-from matplotlib.axes import Axes
 from matplotlib.axis import XAxis, YAxis, Tick
 from matplotlib.backend_bases import RendererBase, MouseButton, MouseEvent
 from matplotlib.cbook import CallbackRegistry
@@ -29,6 +28,7 @@ import numpy as np
 from numpy.typing import ArrayLike
 from typing import Any, Literal, TypeVar, overload
 from matplotlib.typing import ColorType
+from typing_extensions import Self
 
 _T = TypeVar("_T", bound=Artist)
 
@@ -385,8 +385,8 @@ class _AxesBase(martist.Artist):
         bbox_extra_artists: Sequence[Artist] | None = ...,
         for_layout_only: bool = ...
     ) -> Bbox | None: ...
-    def twinx(self) -> Axes: ...
-    def twiny(self) -> Axes: ...
+    def twinx(self, **kwargs) -> Self: ...
+    def twiny(self, **kwargs) -> Self: ...
     def get_shared_x_axes(self) -> cbook.GrouperView: ...
     def get_shared_y_axes(self) -> cbook.GrouperView: ...
     def label_outer(self, remove_inner_ticks: bool = ...) -> None: ...

lib/matplotlib/tests/test_axes.py

@@ -7532,6 +7532,28 @@ def test_twinx_knows_limits():
     assert_array_equal(xtwin.viewLim.intervalx, ax2.viewLim.intervalx)
 
 
+class SubclassAxes(Axes):
+    def __init__(self, *args, foo, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.foo = foo
+
+
+@pytest.mark.parametrize(("axes_class", "kw0", "kw1"), [
+    (Axes, {}, {}),
+    (SubclassAxes, {"foo": 0}, {"foo": 1}),
+])
+def test_twinx_subclass(axes_class, kw0, kw1):
+    fig = plt.figure()
+    classed_ax = fig.add_subplot(axes_class=axes_class, **kw0)
+    for k, v in kw0.items():
+        assert getattr(classed_ax, k) == v
+
+    twin = classed_ax.twinx(**kw1)
+    assert type(twin) is axes_class
+    for k, v in kw1.items():
+        assert getattr(twin, k) == v
+
+
 def test_zero_linewidth():
     # Check that setting a zero linewidth doesn't error
     plt.plot([0, 1], [0, 1], ls='--', lw=0)