[Matplotlib-users] Strange behavior for lognorm colorbar with extend as both

[Chao Y. <cha...@gm...>]

Hi,
I met with a problem using Python to draw graphs. Compare the
following two scripts and attached graphs. For the first one, the left
edge of the colorbar is white. It seems that only when I use
norm=LogNorm() the problem happens. Does anyone know how to solve it?
Thanks!


python1:
from mpl_toolkits.basemap import cm
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm

data = np.tile(np.logspace(-12,0,num=13),(13,1))
print data[0]
bounds = data[0][2:-2]
print bounds
fig,ax=plt.subplots()
im = ax.imshow(data,vmin=bounds[0],vmax=bounds[-1],norm=LogNorm(),cmap
= cm.GMT_seis_r)
cb=fig.colorbar(im,ax=ax,\
                   extend='both',\
                   ticks=bounds,\
                   #default, can be omitted
                   drawedges=False,\
                   shrink=0.6,\
                   orientation='horizontal',\
                   pad=0.02)
plt.show()

python2:

from mpl_toolkits.basemap import cm
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm

data = np.tile(np.arange(-12,0),(13,1))
print data[0]
bounds = data[0][2:-2]
print bounds
fig,ax=plt.subplots()
im = ax.imshow(data,vmin=bounds[0],vmax=bounds[-1],cmap = cm.GMT_seis_r)
cb=fig.colorbar(im,ax=ax,\
                    extend='both',\
                    ticks=bounds,\
                    #default, can be omitted
                    drawedges=False,\
                    shrink=0.6,\
                    orientation='horizontal',\
                    pad=0.02)
plt.show()

Chao

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Chao YUE
Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL)
UMR 1572 CEA-CNRS-UVSQ
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