adding auto ticks example

choldgraf · choldgraf · commit f13c3ae2360c · 2017-07-14T14:22:41.000-05:00
diff --git a/examples/ticks_and_spines/auto_ticks.py b/examples/ticks_and_spines/auto_ticks.py
@@ -0,0 +1,59 @@
+"""
+=================================
+Automatically setting tick labels
+=================================
+
+Setting the behavior of tick auto-placement.
+
+If you don't explicitly set tick positions / labels, Matplotlib will attempt
+to choose them both automatically based on the displayed data and its limits.
+
+By default, this attempts to choose tick positions that are distributed
+along the axis:
+"""
+import matplotlib.pyplot as plt
+import numpy as np
+np.random.seed(19680801)
+rc = plt.rcParams
+
+fig, ax = plt.subplots()
+data = np.random.randn(2, 1000)
+ax.scatter(*data, c=data[1])
+
+################################################################################
+# if we change the X or Y limits, Matplotlib will automatically change the
+# ticks accordingly:
+
+fig, ax = plt.subplots()
+ax.scatter(*data, c=data[1])
+xlim = [-.5, .5]
+ylim = [0, .3]
+ax.set(xlim=xlim, ylim=ylim)
+
+################################################################################
+# Sometimes choosing evenly-distributed ticks results in strange tick positions.
+# If you'd like Matplotlib to keep ticks located at even numbers, you can
+# change this behavior with the following rcParams value:
+
+print(rc['axes.autolimit_mode'])
+
+# Now change this value and see the results
+rc['axes.autolimit_mode'] = 'round_numbers'
+with plt.rc_context(rc=rc):
+    fig, ax = plt.subplots()
+    ax.scatter(*data, c=data[1])
+    ax.set(xlim=xlim, ylim=ylim)
+
+################################################################################
+# You can also alter the location of the ticks at the edge of each axis by
+# changing their margins:
+
+rc['axes.xmargin'] = 0
+rc['axes.ymargin'] = 0
+
+with plt.rc_context(rc=rc):
+    fig, ax = plt.subplots()
+    ax.scatter(*data, c=data[1])
+    ax.set(xlim=xlim, ylim=ylim)
+
+plt.show()
