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I have a code that uses matplotlib (python win32 v2.7.5) to plot contour plots with color bars that are animated or the contour gets updated. In order to update the plot, I delete the color bar axis while keeping the original plot axis untouched. In version 1.1.1 of matplotlib, the program was working okay, however, when I upgraded to 1.2.1 of matplotlib I started to notice my plot is getting squashed to the left by the color bar as seen in the attached images.

In V1.1.1, the plot looked like this after multiple iterations: contour plot using V1.1.1

whereas in V1.2.1 the plot looks now like this: contour plot using V1.2.1

As seen, the major plot is getting pushed to the left even if I am using subplots_adjust.

The code for the above plots is as follows:

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.mlab import bivariate_normal
from matplotlib.colors import LogNorm

delta = 0.5
x = np.arange(-3.0, 4.001, delta)
y = np.arange(-4.0, 3.001, delta)
X, Y = np.meshgrid(x, y)
Z = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
fig  = plt.figure()
fig.subplots_adjust(left=0.1, bottom=0.1, right=0.97, top=0.92)
ax   = fig.add_subplot(1,1,1)
axim = ax.imshow(Z,norm = LogNorm())
cb   = fig.colorbar(axim)

#Note:  These are not replicated, I put them here to show how a refresh of the 
#       contour plot multiple times will look like
fig.delaxes(fig.axes[1])
fig.subplots_adjust(left=0.1, bottom=0.1, right=0.97, top=0.92)
cb   = fig.colorbar(axim)

fig.delaxes(fig.axes[1])
fig.subplots_adjust(left=0.1, bottom=0.1, right=0.97, top=0.92)
cb   = fig.colorbar(axim)

plt.show()

If i delete ALL axis and re-create them each time, then it looks ok even in new version, but I am thinking that this is not efficient process with animation.

Any ideas why what changed in 1.2.1 to make such behavior? Or any other suggestions to make it work again?

Nader
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  • Have a look at [this question/answer](http://stackoverflow.com/questions/16989407/matplotlib-colour-bar-resizing-image/) and [this other question/answer](http://stackoverflow.com/questions/16917836/matplotlib-stretches-histogram2d-vertically) - in those cases `imshow` was the trouble-maker – Schorsch Jun 11 '13 at 23:38
  • The issue is not in imshow, I get the same result with contourf, also notice that my colorbar gets pushed to the left as well, unlike the other cases you mention. – Nader Jun 12 '13 at 16:03

1 Answers1

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In matplotlib 1.4 this pull request was merged adding a remove() method to the colorbar. This method will remove the colorbar and restore the gridspec if needed. Meaning a call to subplots_adjust will work as expected.

If you are stuck with an older version of matplotlib (like I am at the moment), have a look at the changes for colorbar.py in the pull request and you should be able to get it to work.

freidrichen
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