Merge pull request matplotlib#23579 from anntzer/unpar

Remove direct manipulation of HostAxes.parasites by end users.

Author: QuLogic

doc/api/next_api_changes/behavior/23579-AL.rst

@@ -0,0 +1,5 @@
+``HostAxesBase.get_aux_axes`` now defaults to using the same base axes class as the host axes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+If using an ``mpl_toolkits.axisartist``-based host Axes, the parasite Axes will
+also be based on ``mpl_toolkits.axisartist``.  This behavior is consistent with
+``HostAxesBase.twin``, ``HostAxesBase.twinx``, and ``HostAxesBase.twiny``.

examples/axisartist/demo_curvelinear_grid.py

@@ -95,7 +95,6 @@ def curvelinear_test2(fig):
     ax2 = ax1.get_aux_axes(tr)
     # note that ax2.transData == tr + ax1.transData
     # Anything you draw in ax2 will match the ticks and grids of ax1.
-    ax1.parasites.append(ax2)
     ax2.plot(np.linspace(0, 30, 51), np.linspace(10, 10, 51), linewidth=2)
 
     ax2.pcolor(np.linspace(0, 90, 4), np.linspace(0, 10, 4),

examples/axisartist/demo_parasite_axes.py

@@ -17,17 +17,15 @@
 :doc:`/gallery/axisartist/demo_parasite_axes2` example.
 """
 
-from mpl_toolkits.axisartist.parasite_axes import HostAxes, ParasiteAxes
+from mpl_toolkits.axisartist.parasite_axes import HostAxes
 import matplotlib.pyplot as plt
 
 
 fig = plt.figure()
 
 host = fig.add_axes([0.15, 0.1, 0.65, 0.8], axes_class=HostAxes)
-par1 = ParasiteAxes(host, sharex=host)
-par2 = ParasiteAxes(host, sharex=host)
-host.parasites.append(par1)
-host.parasites.append(par2)
+par1 = host.get_aux_axes(viewlim_mode=None, sharex=host)
+par2 = host.get_aux_axes(viewlim_mode=None, sharex=host)
 
 host.axis["right"].set_visible(False)
 

lib/mpl_toolkits/axes_grid1/parasite_axes.py

@@ -99,20 +99,35 @@ def __init__(self, *args, **kwargs):
         self.parasites = []
         super().__init__(*args, **kwargs)
 
-    def get_aux_axes(self, tr=None, viewlim_mode="equal", axes_class=Axes):
+    def get_aux_axes(
+            self, tr=None, viewlim_mode="equal", axes_class=None, **kwargs):
         """
         Add a parasite axes to this host.
 
         Despite this method's name, this should actually be thought of as an
         ``add_parasite_axes`` method.
 
-        *tr* may be `.Transform`, in which case the following relation will
-        hold: ``parasite.transData = tr + host.transData``.  Alternatively, it
-        may be None (the default), no special relationship will hold between
-        the parasite's and the host's ``transData``.
+        Parameters
+        ----------
+        tr : `.Transform` or None, default: None
+            If a `.Transform`, the following relation will hold:
+            ``parasite.transData = tr + host.transData``.
+            If None, the parasite's and the host's ``transData`` are unrelated.
+        viewlim_mode : {"equal", "transform", None}, default: "equal"
+            How the parasite's view limits are set: directly equal to the
+            parent axes ("equal"), equal after application of *tr*
+            ("transform"), or independently (None).
+        axes_class : subclass type of `~.axes.Axes`, optional
+            The `.axes.Axes` subclass that is instantiated.  If None, the base
+            class of the host axes is used.
+        kwargs
+            Other parameters are forwarded to the parasite axes constructor.
         """
+        if axes_class is None:
+            axes_class = self._base_axes_class
         parasite_axes_class = parasite_axes_class_factory(axes_class)
-        ax2 = parasite_axes_class(self, tr, viewlim_mode=viewlim_mode)
+        ax2 = parasite_axes_class(
+            self, tr, viewlim_mode=viewlim_mode, **kwargs)
         # note that ax2.transData == tr + ax1.transData
         # Anything you draw in ax2 will match the ticks and grids of ax1.
         self.parasites.append(ax2)

lib/mpl_toolkits/tests/test_axisartist_axislines.py

@@ -4,7 +4,7 @@
 from matplotlib.transforms import IdentityTransform
 
 from mpl_toolkits.axisartist.axislines import SubplotZero, Subplot
-from mpl_toolkits.axisartist import Axes, SubplotHost, ParasiteAxes
+from mpl_toolkits.axisartist import Axes, SubplotHost
 
 
 @image_comparison(['SubplotZero.png'], style='default')
@@ -81,8 +81,7 @@ def test_ParasiteAxesAuxTrans():
         ax1 = SubplotHost(fig, 1, 3, i+1)
         fig.add_subplot(ax1)
 
-        ax2 = ParasiteAxes(ax1, IdentityTransform())
-        ax1.parasites.append(ax2)
+        ax2 = ax1.get_aux_axes(IdentityTransform(), viewlim_mode=None)
         if name.startswith('pcolor'):
             getattr(ax2, name)(xx, yy, data[:-1, :-1])
         else:

lib/mpl_toolkits/tests/test_axisartist_grid_helper_curvelinear.py

@@ -6,7 +6,6 @@
 from matplotlib.transforms import Affine2D, Transform
 from matplotlib.testing.decorators import image_comparison
 
-from mpl_toolkits.axes_grid1.parasite_axes import ParasiteAxes
 from mpl_toolkits.axisartist import SubplotHost
 from mpl_toolkits.axes_grid1.parasite_axes import host_subplot_class_factory
 from mpl_toolkits.axisartist import angle_helper
@@ -66,8 +65,7 @@ def inverted(self):
     ax1 = SubplotHost(fig, 1, 1, 1, grid_helper=grid_helper)
     fig.add_subplot(ax1)
 
-    ax2 = ParasiteAxes(ax1, tr, viewlim_mode="equal")
-    ax1.parasites.append(ax2)
+    ax2 = ax1.get_aux_axes(tr, viewlim_mode="equal")
     ax2.plot([3, 6], [5.0, 10.])
 
     ax1.set_aspect(1.)
@@ -127,10 +125,9 @@ def test_polar_box():
     axis.get_helper().set_extremes(-180, 90)
 
     # A parasite axes with given transform
-    ax2 = ParasiteAxes(ax1, tr, viewlim_mode="equal")
+    ax2 = ax1.get_aux_axes(tr, viewlim_mode="equal")
     assert ax2.transData == tr + ax1.transData
     # Anything you draw in ax2 will match the ticks and grids of ax1.
-    ax1.parasites.append(ax2)
     ax2.plot(np.linspace(0, 30, 50), np.linspace(10, 10, 50))
 
     ax1.set_aspect(1.)

tutorials/toolkits/axisartist.py

@@ -519,10 +519,9 @@ def inv_tr(x, y):
     ax1 = SubplotHost(fig, 1, 2, 2, grid_helper=grid_helper)
 
     # A parasite axes with given transform
-    ax2 = ParasiteAxesAuxTrans(ax1, tr, "equal")
+    ax2 = ax1.get_aux_axes(tr, "equal")
     # note that ax2.transData == tr + ax1.transData
     # Anything you draw in ax2 will match the ticks and grids of ax1.
-    ax1.parasites.append(ax2)
 
 .. figure:: ../../gallery/axisartist/images/sphx_glr_demo_curvelinear_grid_001.png
    :target: ../../gallery/axisartist/demo_curvelinear_grid.html