Merge fix of standard example animation into APNG branch.

Since the APNG code I'm about to commit rejects frames of different sizes,
the doctest for show will fail unless the example gets fixed.

src/sage/plot/animate.py

@@ -136,8 +136,9 @@ class Animation(SageObject):
 
     EXAMPLES::
 
-        sage: a = animate([sin(x + float(k)) for k in srange(0,2*pi,0.3)],
-        ....:                xmin=0, xmax=2*pi, figsize=[2,1])
+        sage: a = animate([plot(sin(x + float(k)), (x,0,2*pi))
+        ....:              for k in srange(0,2*pi,0.3)],
+        ....:             ymin=-1, ymax=1, figsize=[2,1])
         sage: a
         Animation with 21 frames
         sage: a[:5]
@@ -195,8 +196,9 @@ def __init__(self, v=None, **kwds):
 
         EXAMPLES::
 
-            sage: a = animate([sin(x + float(k)) for k in srange(0,2*pi,0.3)],
-            ....:                xmin=0, xmax=2*pi, figsize=[2,1]) # indirect doctest
+            sage: a = animate([plot(sin(x + float(k)), (x,0,2*pi))
+            ....:              for k in srange(0,2*pi,0.3)],
+            ....:             ymin=-1, ymax=1, figsize=[2,1])
             sage: a
             Animation with 21 frames
         """
@@ -517,8 +519,9 @@ def gif(self, delay=20, savefile=None, iterations=0, show_path=False,
 
         EXAMPLES::
 
-            sage: a = animate([sin(x + float(k)) for k in srange(0,2*pi,0.7)],
-            ....:                xmin=0, xmax=2*pi, figsize=[2,1])
+            sage: a = animate([plot(sin(x + float(k)), (x,0,2*pi))
+            ....:              for k in srange(0,2*pi,0.7)],
+            ....:             ymin=-1, ymax=1, figsize=[2,1])
             sage: dir = tmp_dir()
             sage: a.gif()              # not tested
             sage: a.gif(savefile=dir + 'my_animation.gif', delay=35, iterations=3)  # optional -- ImageMagick
@@ -608,9 +611,10 @@ def show(self, delay=20, iterations=0):
 
         EXAMPLES::
 
-            sage: a = animate([sin(x + float(k)) for k in srange(0,2*pi,0.7)],
-            ....:                xmin=0, xmax=2*pi, figsize=[2,1])
-            sage: a.show()       # optional -- ImageMagick
+            sage: a = animate([plot(sin(x + float(k)), (x,0,2*pi))
+            ....:              for k in srange(0,2*pi,0.7)],
+            ....:             ymin=-1, ymax=1, figsize=[2,1])
+            sage: a.show()               # optional -- ImageMagick
 
         The preceding will loop the animation forever. If you want to show
         only three iterations instead::
@@ -706,8 +710,9 @@ def ffmpeg(self, savefile=None, show_path=False, output_format=None,
 
         EXAMPLES::
 
-            sage: a = animate([sin(x + float(k)) for k in srange(0,2*pi,0.7)],
-            ....:                xmin=0, xmax=2*pi, figsize=[2,1])
+            sage: a = animate([plot(sin(x + float(k)), (x,0,2*pi))
+            ....:              for k in srange(0,2*pi,0.7)],
+            ....:             ymin=-1, ymax=1, figsize=[2,1])
             sage: dir = tmp_dir()
             sage: a.ffmpeg(savefile=dir + 'new.mpg')       # optional -- ffmpeg
             sage: a.ffmpeg(savefile=dir + 'new.avi')       # optional -- ffmpeg
@@ -829,8 +834,9 @@ def save(self, filename=None, show_path=False, use_ffmpeg=False):
 
         EXAMPLES::
 
-            sage: a = animate([sin(x + float(k)) for k in srange(0,2*pi,0.7)],
-            ....:                xmin=0, xmax=2*pi, figsize=[2,1])
+            sage: a = animate([plot(sin(x + float(k)), (x,0,2*pi))
+            ....:              for k in srange(0,2*pi,0.7)],
+            ....:             ymin=-1, ymax=1, figsize=[2,1])
             sage: dir = tmp_dir()
             sage: a.save()         # not tested
             sage: a.save(dir + 'wave.gif')   # optional -- ImageMagick