Suppose I want to make 2+ heatmaps (on the same, or different Figures) and have the color<->value mapping be the same among them.
By default, the extreme values in the colormap (say jet) will be used for the dynamic range of each heatmap individually (i.e. each call to imshow), and I'd like to force the mapping to be the same, i.e. use the global dynamic range.
I think an equivalent statement is that I'd like to somehow specify an absolute mapping, whereas the behavior of imshow given a cmap object, is relative to the dynamic range of the input.