[Matplotlib-users] Bug in colorbar()

[Jeffrey S. <jef...@gm...>]

I am trying to make a plot with a colorbar that has a reduced axis over
which the colorbar is executed.

This is set via passing in a norm to contourf:
        logNorm = colors.Normalize(vmax=0,vmin=-100)
        surf = ax.contourf(X,Y,logZ, map_scale, cmap=cm.jet, norm=logNorm)

The output of this will have the colorbar extend to the full range of the
data and not limited by the norm set:

cbar = fig.colorbar(surf, shrink=0.70, aspect=36, fraction=.15,pad=.03)

so I assumed modifying by setting the norm like this would do the trick:

cbar = fig.colorbar(surf, shrink=0.70, aspect=36, fraction=.15,pad=.03,
norm=logNorm)

This isn't what happens. norm has no effect. The norm is recognized but not
passed to ColorbarBase is my guess from doing this instead to get the
desired effect:

        axcb, _ = mpl.colorbar.make_axes_gridspec(ax, shrink=0.7)
        cbar = mpl.colorbar.ColorbarBase(axcb, cmap=cm.jet, norm=logNorm)



Is this a bug or any reason why the norm is not passed through if specified
in colorbar??