Merge pull request matplotlib#3099 from rougier/unchained

New animation example (Joy Division's Unchained Love cover)

examples/animation/unchained.py

@@ -0,0 +1,65 @@
+"""
+Comparative path demonstration of frequency from a fake signal of a pulsar.
+(mostly known because of the cover for Joy Division's Unknown Pleasures)
+
+Author: Nicolas P. Rougier
+"""
+import numpy as np
+import matplotlib.pyplot as plt
+import matplotlib.animation as animation
+
+# Create new Figure with black background
+fig = plt.figure(figsize=(8, 8), facecolor='black')
+
+# Add a subplot with no frame
+ax = plt.subplot(111, frameon=False)
+
+# Generate random data
+data = np.random.uniform(0, 1, (64, 75))
+X = np.linspace(-1, 1, data.shape[-1])
+G = 1.5 * np.exp(-4 * X * X)
+
+# Generate line plots
+lines = []
+for i in range(len(data)):
+    # Small reduction of the X extents to get a cheap perspective effect
+    xscale = 1 - i / 200.
+    # Same for linewidth (thicker strokes on bottom)
+    lw = 1.5 - i / 100.0
+    line, = ax.plot(xscale * X, i + G * data[i], color="w", lw=lw)
+    lines.append(line)
+
+# Set y limit (or first line is cropped because of thickness)
+ax.set_ylim(-1, 70)
+
+# No ticks
+ax.set_xticks([])
+ax.set_yticks([])
+
+# 2 part titles to get different font weights
+ax.text(0.5, 1.0, "MATPLOTLIB ", transform=ax.transAxes,
+        ha="right", va="bottom", color="w",
+        family="sans-serif", fontweight="light", fontsize=16)
+ax.text(0.5, 1.0, "UNCHAINED", transform=ax.transAxes,
+        ha="left", va="bottom", color="w",
+        family="sans-serif", fontweight="bold", fontsize=16)
+
+# Update function
+def update(*args):
+    # Shift all data to the right
+    data[:, 1:] = data[:, :-1]
+
+    # Fill-in new values
+    data[:, 0] = np.random.uniform(0, 1, len(data))
+
+    # Update data
+    for i in range(len(data)):
+        lines[i].set_ydata(i + G * data[i])
+
+    # Return modified artists
+    return lines
+
+# Construct the animation, using the update function as the animation
+# director.
+anim = animation.FuncAnimation(fig, update, interval=10)
+plt.show()