Prefer plot() to scatter() in examples.

anntzer · anntzer · commit e12f26464303 · 2019-05-10T00:35:33.000+02:00
... when markers don't vary in size or shape.

The docstring of scatter() suggests to do so (for performance), so let's
showcase it.
diff --git a/examples/axes_grid1/scatter_hist_locatable_axes.py b/examples/axes_grid1/scatter_hist_locatable_axes.py
@@ -20,7 +20,7 @@
 fig, axScatter = plt.subplots(figsize=(5.5, 5.5))
 
 # the scatter plot:
-axScatter.scatter(x, y)
+axScatter.scatter(x, y, ".")
 axScatter.set_aspect(1.)
 
 # create new axes on the right and on the top of the current axes
diff --git a/examples/axisartist/demo_floating_axes.py b/examples/axisartist/demo_floating_axes.py
@@ -149,12 +149,12 @@ def setup_axes3(fig, rect):
 ax2, aux_ax2 = setup_axes2(fig, 132)
 theta = np.random.rand(10)*.5*np.pi
 radius = np.random.rand(10) + 1.
-aux_ax2.scatter(theta, radius)
+aux_ax2.plot(theta, radius, ".")
 
 ax3, aux_ax3 = setup_axes3(fig, 133)
 
 theta = (8 + np.random.rand(10)*(14 - 8))*15.  # in degrees
 radius = np.random.rand(10)*14000.
-aux_ax3.scatter(theta, radius)
+aux_ax3.plot(theta, radius, ".")
 
 plt.show()
diff --git a/examples/images_contours_and_fields/quiver_demo.py b/examples/images_contours_and_fields/quiver_demo.py
@@ -35,7 +35,7 @@
                pivot='mid', units='inches')
 qk = ax2.quiverkey(Q, 0.9, 0.9, 1, r'$1 \frac{m}{s}$', labelpos='E',
                    coordinates='figure')
-ax2.scatter(X[::3, ::3], Y[::3, ::3], color='r', s=5)
+ax2.plot(X[::3, ::3], Y[::3, ::3], '.', ms=3, c='r')
 
 ###############################################################################
 
@@ -48,7 +48,7 @@
                scale=1 / 0.15)
 qk = ax3.quiverkey(Q, 0.9, 0.9, 1, r'$1 \frac{m}{s}$', labelpos='E',
                    coordinates='figure')
-ax3.scatter(X, Y, color='0.5', s=1)
+ax3.plot(X, Y, '.', color='0.5', ms=3)
 
 plt.show()
 
diff --git a/examples/lines_bars_and_markers/scatter_star_poly.py b/examples/lines_bars_and_markers/scatter_star_poly.py
@@ -3,10 +3,9 @@
 Scatter Star Poly
 =================
 
-Create multiple scatter plots with different
-star symbols.
-
+Create multiple scatter plots with different star symbols.
 """
+
 import numpy as np
 import matplotlib.pyplot as plt
 
diff --git a/examples/statistics/confidence_ellipse.py b/examples/statistics/confidence_ellipse.py
@@ -142,14 +142,14 @@ def get_correlated_dataset(n, dependency, mu, scale):
 fig, axs = plt.subplots(1, 3, figsize=(9, 3))
 for ax, (title, dependency) in zip(axs, PARAMETERS.items()):
     x, y = get_correlated_dataset(800, dependency, mu, scale)
-    ax.scatter(x, y, s=0.5)
+    ax.plot(x, y, ".", ms=1)
 
     ax.axvline(c='grey', lw=1)
     ax.axhline(c='grey', lw=1)
 
     confidence_ellipse(x, y, ax, edgecolor='red')
 
-    ax.scatter(mu[0], mu[1], c='red', s=3)
+    ax.plot(mu[0], mu[1], ".", ms=1, c="r")
     ax.set_title(title)
 
 plt.show()
@@ -175,7 +175,7 @@ def get_correlated_dataset(n, dependency, mu, scale):
 ax_nstd.axhline(c='grey', lw=1)
 
 x, y = get_correlated_dataset(500, dependency_nstd, mu, scale)
-ax_nstd.scatter(x, y, s=0.5)
+ax_nstd.plot(x, y, ".", ms=1)
 
 confidence_ellipse(x, y, ax_nstd, n_std=1,
     label=r'$1\sigma$', edgecolor='firebrick')
@@ -184,7 +184,7 @@ def get_correlated_dataset(n, dependency, mu, scale):
 confidence_ellipse(x, y, ax_nstd, n_std=3,
     label=r'$3\sigma$', edgecolor='blue', linestyle=':')
 
-ax_nstd.scatter(mu[0], mu[1], c='red', s=3)
+ax_nstd.plot(mu[0], mu[1], ".", ms=1, c="r")
 ax_nstd.set_title('Different standard deviations')
 ax_nstd.legend()
 plt.show()
@@ -215,8 +215,8 @@ def get_correlated_dataset(n, dependency, mu, scale):
 confidence_ellipse(x, y, ax_kwargs,
     alpha=0.5, facecolor='pink', edgecolor='purple', zorder=0)
 
-ax_kwargs.scatter(x, y, s=0.5)
-ax_kwargs.scatter(mu[0], mu[1], c='red', s=3)
+ax_kwargs.plot(x, y, ".", ms=1)
+ax_kwargs.plot(mu[0], mu[1], ".", ms=1, c="r")
 ax_kwargs.set_title(f'Using kwargs')
 
 fig.subplots_adjust(hspace=0.25)
diff --git a/examples/statistics/customized_violin.py b/examples/statistics/customized_violin.py
@@ -63,7 +63,7 @@ def set_axis_style(ax, labels):
 whiskersMin, whiskersMax = whiskers[:, 0], whiskers[:, 1]
 
 inds = np.arange(1, len(medians) + 1)
-ax2.scatter(inds, medians, marker='o', color='white', s=30, zorder=3)
+ax2.plot(inds, medians, 'o', color='white', zorder=3)
 ax2.vlines(inds, quartile1, quartile3, color='k', linestyle='-', lw=5)
 ax2.vlines(inds, whiskersMin, whiskersMax, color='k', linestyle='-', lw=1)
 
diff --git a/examples/text_labels_and_annotations/text_rotation.py b/examples/text_labels_and_annotations/text_rotation.py
@@ -29,7 +29,7 @@ def addtext(ax, props):
     ax.text(3.5, 0.5, 'text 225', props, rotation=225)
     ax.text(4.5, 0.5, 'text -45', props, rotation=-45)
     for x in range(0, 5):
-        ax.scatter(x + 0.5, 0.5, color='r', alpha=0.5)
+        ax.plot(x + 0.5, 0.5, 'ro', alpha=0.5)
     ax.set_yticks([0, .5, 1])
     ax.set_xlim(0, 5)
     ax.grid(True)
diff --git a/examples/userdemo/annotate_text_arrow.py b/examples/userdemo/annotate_text_arrow.py
@@ -16,8 +16,8 @@
 x2 = 1. + np.random.randn(100)
 y2 = 1. + np.random.randn(100)
 
-ax.scatter(x1, y1, color="r")
-ax.scatter(x2, y2, color="g")
+ax.plot(x1, y1, ".", c="r")
+ax.plot(x2, y2, ".", c="g")
 
 bbox_props = dict(boxstyle="round", fc="w", ec="0.5", alpha=0.9)
 ax.text(-2, -2, "Sample A", ha="center", va="center", size=20,
