DOC: Consolidate shared axis examples

This replaces the two existing examples into one single example, that
shows the basic concept of sharing and links out for further details.

For now, the link goes to the subplots_demo. The sharing part should be
refactored out into a tutorial. But that's a separate topic, and the
link anchor will move along in such a refactoring.

Author: timhoffm

galleries/examples/subplots_axes_and_figures/share_axis_lims_views.py

@@ -3,46 +3,38 @@
 Shared axis
 ===========
 
-You can share the x- or y-axis limits for one axis with another by
-passing an `~.axes.Axes` instance as a *sharex* or *sharey* keyword argument.
-
-Changing the axis limits on one Axes will be reflected automatically
-in the other, and vice-versa, so when you navigate with the toolbar
-the Axes will follow each other on their shared axis.  Ditto for
-changes in the axis scaling (e.g., log vs. linear).  However, it is
-possible to have differences in tick labeling, e.g., you can selectively
-turn off the tick labels on one Axes.
-
-The example below shows how to customize the tick labels on the
-various axes.  Shared axes share the tick locator, tick formatter,
-view limits, and transformation (e.g., log, linear). But the tick labels
-themselves do not share properties.  This is a feature and not a bug,
-because you may want to make the tick labels smaller on the upper
-axes, e.g., in the example below.
+Use axis sharing when you want to compare data across multiple subplots, and want to
+ensure they are on the same scale. To do so, pass ``sharex=True`` and/or ``sharey=True``
+to `~.pyplot.subplots`.
+
+This ensures the x- or y-axis limits are synchronized across the subplots. Autoscaling
+considers the data on all Axes and any limit changes, including interactive zoom
+and pan, will affect all shared axes.
+
+The plot below illustrates this by showing two different time-series and using *sharex*
+to ensure the times are aligned.
+
+For more info see :ref:`sharing-axes`.
+
+.. redirect-from:: /gallery/subplots_axes_and_figures/share_axis_lims_views
 """
 import matplotlib.pyplot as plt
 import numpy as np
 
-t = np.arange(0.01, 5.0, 0.01)
-s1 = np.sin(2 * np.pi * t)
-s2 = np.exp(-t)
-s3 = np.sin(4 * np.pi * t)
-
-ax1 = plt.subplot(311)
-plt.plot(t, s1)
-# reduce the fontsize of the tick labels
-plt.tick_params('x', labelsize=6)
-
-# share x only
-ax2 = plt.subplot(312, sharex=ax1)
-plt.plot(t, s2)
-# make these tick labels invisible
-plt.tick_params('x', labelbottom=False)
-
-# share x and y
-ax3 = plt.subplot(313, sharex=ax1, sharey=ax1)
-plt.plot(t, s3)
-plt.xlim(0.01, 5.0)
+t1 = np.linspace(0, 8, 201)
+y1 = np.sin(2 * np.pi * t1)
+t2 = np.linspace(2, 10, 201)
+y2 = 20 * np.cos(2 * np.pi * t2)**2 * np.exp(-0.3*t2)
+
+fig, (ax1, ax2) = plt.subplots(2, sharex=True)
+
+ax1.plot(t1, y1)
+ax1.set_ylabel("Signal 1")
+
+ax2.plot(t2, y2)
+ax2.set_ylabel("Signal 2")
+ax2.set_xlabel("Time (s)")
+
 plt.show()
 
 # %%

galleries/examples/subplots_axes_and_figures/shared_axis_demo.py

@@ -108,6 +108,8 @@
     ax.label_outer()
 
 # %%
+# .. _sharing-axes:
+#
 # Sharing axes
 # """"""""""""
 #