Example: Add stem3d example

harshanavkis · harshanavkis · commit fbb184d2b2cd · 2019-09-13T22:19:01.000+05:30
This commit provides an example on generating 3d stem plots.

Signed-off-by: harshanavkis &lt;harshanavkis@gmail.com&gt;
diff --git a/examples/mplot3d/stem3d.py b/examples/mplot3d/stem3d.py
@@ -0,0 +1,41 @@
+'''
+==============
+3D stemplot
+==============
+
+Demonstration of a basic stemplot in 3D.
+'''
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+# Fixing random state for reproducibility
+np.random.seed(19680801)
+
+
+def randrange(n, vmin, vmax):
+    '''
+    Helper function to make an array of random numbers having shape (n, )
+    with each number distributed Uniform(vmin, vmax).
+    '''
+    return (vmax - vmin)*np.random.rand(n) + vmin
+
+fig = plt.figure()
+ax = fig.add_subplot(111, projection='3d')
+
+n = 100
+
+# For each set of style and range settings, plot n random points in the box
+# defined by x in [23, 32], y in [0, 100], z in [zlow, zhigh].
+for zlow, zhigh in [(-50, -25), (-30, -5)]:
+    xs = randrange(n, 23, 32)
+    ys = randrange(n, 0, 100)
+    zs = randrange(n, zlow, zhigh)
+    ax.stem(xs, ys, zs, linefmt='grey', markerfmt='D', bottom=1.1,
+    		use_line_collection=True)
+
+ax.set_xlabel('X Label')
+ax.set_ylabel('Y Label')
+ax.set_zlabel('Z Label')
+
+plt.show()
