Colorbar plot with matplotlib ... but in gray?

Question

Is it possible to change the colors of the colorbar plot to grayscale ? At the moment I plot them like this:

ax = fig.add_subplot(326,title='Title')
cax = ax.matshow(newcm)
fig.colorbar(cax)

ax.set_xticklabels(['']+alpha)
ax.set_yticklabels(['']+alpha)
pl.show()

Though off course they appear in color. But is it possible to change them to grayscale ? And how ?

Answer 1

The colorbar shows the colormap used for the data. If you want different colors, specify a different colormap in your matshow call:

ax.matshow(newcm, cmap=pyplot.cm.Greys)

You can see available colormaps at http://www.scipy.org/Cookbook/Matplotlib/Show_colormaps . There a couple grayscale options.