Replace use of pyplot with OO api in some examples (#19359)

ianthomas23 · web-flow · commit 07aa92b15195 · 2021-01-26T01:07:53.000+01:00
* Replace use of pyplot with OO api in some examples

* flake8 fix
diff --git a/examples/event_handling/trifinder_event_demo.py b/examples/event_handling/trifinder_event_demo.py
@@ -29,7 +29,7 @@ def on_mouse_move(event):
     else:
         tri = trifinder(event.xdata, event.ydata)
     update_polygon(tri)
-    plt.title('In triangle %i' % tri)
+    ax.set_title(f'In triangle {tri}')
     event.canvas.draw()
 
 
@@ -52,10 +52,10 @@ def on_mouse_move(event):
 trifinder = triang.get_trifinder()
 
 # Setup plot and callbacks.
-plt.subplot(aspect='equal')
-plt.triplot(triang, 'bo-')
+fig, ax = plt.subplots(subplot_kw={'aspect': 'equal'})
+ax.triplot(triang, 'bo-')
 polygon = Polygon([[0, 0], [0, 0]], facecolor='y')  # dummy data for (xs, ys)
 update_polygon(-1)
-plt.gca().add_patch(polygon)
-plt.gcf().canvas.mpl_connect('motion_notify_event', on_mouse_move)
+ax.add_patch(polygon)
+fig.canvas.mpl_connect('motion_notify_event', on_mouse_move)
 plt.show()
diff --git a/examples/lines_bars_and_markers/psd_demo.py b/examples/lines_bars_and_markers/psd_demo.py
@@ -26,10 +26,9 @@
 cnse = cnse[:len(t)]
 s = 0.1 * np.sin(2 * np.pi * t) + cnse
 
-plt.subplot(211)
-plt.plot(t, s)
-plt.subplot(212)
-plt.psd(s, 512, 1 / dt)
+fig, (ax0, ax1) = plt.subplots(2, 1)
+ax0.plot(t, s)
+ax1.psd(s, 512, 1 / dt)
 
 plt.show()
 
@@ -72,7 +71,7 @@
 ax2.psd(y, NFFT=len(t), pad_to=len(t), Fs=fs)
 ax2.psd(y, NFFT=len(t), pad_to=len(t) * 2, Fs=fs)
 ax2.psd(y, NFFT=len(t), pad_to=len(t) * 4, Fs=fs)
-plt.title('zero padding')
+ax2.set_title('zero padding')
 
 # Plot the PSD with different block sizes, Zero pad to the length of the
 # original data sequence.
@@ -81,7 +80,7 @@
 ax3.psd(y, NFFT=len(t) // 2, pad_to=len(t), Fs=fs)
 ax3.psd(y, NFFT=len(t) // 4, pad_to=len(t), Fs=fs)
 ax3.set_ylabel('')
-plt.title('block size')
+ax3.set_title('block size')
 
 # Plot the PSD with different amounts of overlap between blocks
 ax4 = fig.add_subplot(gs[1, 2], sharex=ax2, sharey=ax2)
@@ -91,7 +90,7 @@
 ax4.psd(y, NFFT=len(t) // 2, pad_to=len(t),
         noverlap=int(0.2 * len(t) / 2.), Fs=fs)
 ax4.set_ylabel('')
-plt.title('overlap')
+ax4.set_title('overlap')
 
 plt.show()
 
diff --git a/examples/misc/custom_projection.py b/examples/misc/custom_projection.py
@@ -443,8 +443,8 @@ def _get_core_transform(self, resolution):
 if __name__ == '__main__':
     import matplotlib.pyplot as plt
     # Now make a simple example using the custom projection.
-    plt.subplot(projection="custom_hammer")
-    p = plt.plot([-1, 1, 1], [-1, -1, 1], "o-")
-    plt.grid(True)
+    fig, ax = plt.subplots(subplot_kw={'projection': 'custom_hammer'})
+    ax.plot([-1, 1, 1], [-1, -1, 1], "o-")
+    ax.grid()
 
     plt.show()
diff --git a/examples/scales/symlog_demo.py b/examples/scales/symlog_demo.py
@@ -1,3 +1,4 @@
+
 """
 ===========
 Symlog Demo
@@ -12,24 +13,23 @@
 x = np.arange(-50.0, 50.0, dt)
 y = np.arange(0, 100.0, dt)
 
-plt.subplot(311)
-plt.plot(x, y)
-plt.xscale('symlog')
-plt.ylabel('symlogx')
-plt.grid(True)
-plt.gca().xaxis.grid(True, which='minor')  # minor grid on too
-
-plt.subplot(312)
-plt.plot(y, x)
-plt.yscale('symlog')
-plt.ylabel('symlogy')
-
-plt.subplot(313)
-plt.plot(x, np.sin(x / 3.0))
-plt.xscale('symlog')
-plt.yscale('symlog', linthresh=0.015)
-plt.grid(True)
-plt.ylabel('symlog both')
-
-plt.tight_layout()
+fig, (ax0, ax1, ax2) = plt.subplots(nrows=3)
+
+ax0.plot(x, y)
+ax0.set_xscale('symlog')
+ax0.set_ylabel('symlogx')
+ax0.grid()
+ax0.xaxis.grid(which='minor')  # minor grid on too
+
+ax1.plot(y, x)
+ax1.set_yscale('symlog')
+ax1.set_ylabel('symlogy')
+
+ax2.plot(x, np.sin(x / 3.0))
+ax2.set_xscale('symlog')
+ax2.set_yscale('symlog', linthresh=0.015)
+ax2.grid()
+ax2.set_ylabel('symlog both')
+
+fig.tight_layout()
 plt.show()
diff --git a/examples/shapes_and_collections/ellipse_demo.py b/examples/shapes_and_collections/ellipse_demo.py
@@ -49,14 +49,14 @@
 angle_step = 45  # degrees
 angles = np.arange(0, 180, angle_step)
 
-ax = plt.subplot(aspect='equal')
+fig, ax = plt.subplots(subplot_kw={'aspect': 'equal'})
 
 for angle in angles:
     ellipse = Ellipse((0, 0), 4, 2, angle=angle, alpha=0.1)
     ax.add_artist(ellipse)
 
-plt.xlim(-2.2, 2.2)
-plt.ylim(-2.2, 2.2)
+ax.set_xlim(-2.2, 2.2)
+ax.set_ylim(-2.2, 2.2)
 
 plt.show()
 
diff --git a/examples/text_labels_and_annotations/multiline.py b/examples/text_labels_and_annotations/multiline.py
@@ -7,39 +7,39 @@
 import matplotlib.pyplot as plt
 import numpy as np
 
-plt.figure(figsize=(7, 4))
-ax = plt.subplot(121)
-ax.set_aspect(1)
-plt.plot(np.arange(10))
-plt.xlabel('this is a xlabel\n(with newlines!)')
-plt.ylabel('this is vertical\ntest', multialignment='center')
-plt.text(2, 7, 'this is\nyet another test',
+fig, (ax0, ax1) = plt.subplots(ncols=2, figsize=(7, 4))
+
+ax0.set_aspect(1)
+ax0.plot(np.arange(10))
+ax0.set_xlabel('this is a xlabel\n(with newlines!)')
+ax0.set_ylabel('this is vertical\ntest', multialignment='center')
+ax0.text(2, 7, 'this is\nyet another test',
          rotation=45,
          horizontalalignment='center',
          verticalalignment='top',
          multialignment='center')
 
-plt.grid(True)
+ax0.grid()
 
-plt.subplot(122)
 
-plt.text(0.29, 0.4, "Mat\nTTp\n123", size=18,
+ax1.text(0.29, 0.4, "Mat\nTTp\n123", size=18,
          va="baseline", ha="right", multialignment="left",
          bbox=dict(fc="none"))
 
-plt.text(0.34, 0.4, "Mag\nTTT\n123", size=18,
+ax1.text(0.34, 0.4, "Mag\nTTT\n123", size=18,
          va="baseline", ha="left", multialignment="left",
          bbox=dict(fc="none"))
 
-plt.text(0.95, 0.4, "Mag\nTTT$^{A^A}$\n123", size=18,
+ax1.text(0.95, 0.4, "Mag\nTTT$^{A^A}$\n123", size=18,
          va="baseline", ha="right", multialignment="left",
          bbox=dict(fc="none"))
 
-plt.xticks([0.2, 0.4, 0.6, 0.8, 1.],
-           ["Jan\n2009", "Feb\n2009", "Mar\n2009", "Apr\n2009", "May\n2009"])
+ax1.set_xticks([0.2, 0.4, 0.6, 0.8, 1.])
+ax1.set_xticklabels(["Jan\n2009", "Feb\n2009", "Mar\n2009", "Apr\n2009",
+                     "May\n2009"])
 
-plt.axhline(0.4)
-plt.title("test line spacing for multiline text")
+ax1.axhline(0.4)
+ax1.set_title("test line spacing for multiline text")
 
-plt.subplots_adjust(bottom=0.25, top=0.75)
+fig.subplots_adjust(bottom=0.25, top=0.75)
 plt.show()
diff --git a/examples/userdemo/simple_legend01.py b/examples/userdemo/simple_legend01.py
@@ -7,18 +7,20 @@
 import matplotlib.pyplot as plt
 
 
-plt.subplot(211)
-plt.plot([1, 2, 3], label="test1")
-plt.plot([3, 2, 1], label="test2")
+fig = plt.figure()
+
+ax = fig.add_subplot(211)
+ax.plot([1, 2, 3], label="test1")
+ax.plot([3, 2, 1], label="test2")
 # Place a legend above this subplot, expanding itself to
 # fully use the given bounding box.
-plt.legend(bbox_to_anchor=(0., 1.02, 1., .102), loc='lower left',
+ax.legend(bbox_to_anchor=(0., 1.02, 1., .102), loc='lower left',
            ncol=2, mode="expand", borderaxespad=0.)
 
-plt.subplot(223)
-plt.plot([1, 2, 3], label="test1")
-plt.plot([3, 2, 1], label="test2")
+ax = fig.add_subplot(223)
+ax.plot([1, 2, 3], label="test1")
+ax.plot([3, 2, 1], label="test2")
 # Place a legend to the right of this smaller subplot.
-plt.legend(bbox_to_anchor=(1.05, 1), loc='upper left', borderaxespad=0.)
+ax.legend(bbox_to_anchor=(1.05, 1), loc='upper left', borderaxespad=0.)
 
 plt.show()
