importmatplotlib.pyplotaspltimportnumpyasnp# setup some generic dataN=37x,y=np.mgrid[:N,:N]Z=(np.cos(x*0.2)+np.sin(y*0.3))# mask out the negative and positive values, respectivelyZpos=np.ma.masked_less(Z,0)Zneg=np.ma.masked_greater(Z,0)fig,(ax1,ax2,ax3)=plt.subplots(figsize=(13,3),ncols=3)# plot just the positive data and save the# color "mappable" object returned by ax1.imshowpos=ax1.imshow(Zpos,cmap='Blues',interpolation='none')# add the colorbar using the figure's method,# telling which mappable we're talking about and# which Axes object it should be nearfig.colorbar(pos,ax=ax1)# repeat everything above for the negative data# you can specify location, anchor and shrink the colorbarneg=ax2.imshow(Zneg,cmap='Reds_r',interpolation='none')fig.colorbar(neg,ax=ax2,location='right',anchor=(0,0.3),shrink=0.7)# Plot both positive and negative values between +/- 1.2pos_neg_clipped=ax3.imshow(Z,cmap='RdBu',vmin=-1.2,vmax=1.2,interpolation='none')# Add minorticks on the colorbar to make it easy to read the# values off the colorbar.cbar=fig.colorbar(pos_neg_clipped,ax=ax3,extend='both')cbar.minorticks_on()plt.show()

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