Remove dynamic_image, rename dynamic_image2, restore animate_decay.

anntzer · anntzer · commit 5f0a823d3eff · 2018-01-17T16:31:40.000-05:00
diff --git a/doc/api/animation_api.rst b/doc/api/animation_api.rst
@@ -129,9 +129,9 @@ Examples
 .. toctree::
    :maxdepth: 1
 
+   ../gallery/animation/animate_decay
    ../gallery/animation/bayes_update
    ../gallery/animation/double_pendulum_sgskip
-   ../gallery/animation/dynamic_image
    ../gallery/animation/histogram
    ../gallery/animation/rain
    ../gallery/animation/random_walk
@@ -148,7 +148,7 @@ Examples
 .. toctree::
    :maxdepth: 1
 
-   ../gallery/animation/dynamic_image2
+   ../gallery/animation/dynamic_image
 
 Writer Classes
 ==============
diff --git a/examples/animation/animate_decay.py b/examples/animation/animate_decay.py
@@ -0,0 +1,54 @@
+"""
+=====
+Decay
+=====
+
+This example showcases:
+- using a generator to drive an animation,
+- changing axes limits during an animation.
+"""
+
+import numpy as np
+import matplotlib.pyplot as plt
+import matplotlib.animation as animation
+
+
+def data_gen(t=0):
+    cnt = 0
+    while cnt < 1000:
+        cnt += 1
+        t += 0.1
+        yield t, np.sin(2*np.pi*t) * np.exp(-t/10.)
+
+
+def init():
+    ax.set_ylim(-1.1, 1.1)
+    ax.set_xlim(0, 10)
+    del xdata[:]
+    del ydata[:]
+    line.set_data(xdata, ydata)
+    return line,
+
+fig, ax = plt.subplots()
+line, = ax.plot([], [], lw=2)
+ax.grid()
+xdata, ydata = [], []
+
+
+def run(data):
+    # update the data
+    t, y = data
+    xdata.append(t)
+    ydata.append(y)
+    xmin, xmax = ax.get_xlim()
+
+    if t >= xmax:
+        ax.set_xlim(xmin, 2*xmax)
+        ax.figure.canvas.draw()
+    line.set_data(xdata, ydata)
+
+    return line,
+
+ani = animation.FuncAnimation(fig, run, data_gen, blit=False, interval=10,
+                              repeat=False, init_func=init)
+plt.show()
diff --git a/examples/animation/dynamic_image.py b/examples/animation/dynamic_image.py
@@ -1,7 +1,7 @@
 """
-==============
-Animated image
-==============
+=================================================
+Animated image using a precomputed list of images
+=================================================
 
 """
 
@@ -17,18 +17,18 @@ def f(x, y):
 
 x = np.linspace(0, 2 * np.pi, 120)
 y = np.linspace(0, 2 * np.pi, 100).reshape(-1, 1)
-
-im = plt.imshow(f(x, y), animated=True)
-
-
-def updatefig(*args):
-    global x, y
+# ims is a list of lists, each row is a list of artists to draw in the
+# current frame; here we are just animating one artist, the image, in
+# each frame
+ims = []
+for i in range(60):
     x += np.pi / 15.
     y += np.pi / 20.
-    im.set_array(f(x, y))
-    return im,
+    im = plt.imshow(f(x, y), animated=True)
+    ims.append([im])
 
-ani = animation.FuncAnimation(fig, updatefig, interval=50, blit=True)
+ani = animation.ArtistAnimation(fig, ims, interval=50, blit=True,
+                                repeat_delay=1000)
 
 # To save the animation, use e.g.
 #
diff --git a/examples/animation/dynamic_image2.py b/examples/animation/dynamic_image2.py
