// Set up a colormap:
// use copy so that we do not mutate the global colormap instance
palette = copy(plt.cm.gray)
palette.set_over("r", 1.0)palette.set_under("g", 1.0)
palette.set_bad("b", 1.0)
// Alternatively, we could use
// palette.set_bad(alpha = 0.0)
// to make the bad region transparent. This is the default.
After Change
Z = (Z1 - Z2) * 2
// Set up a colormap:
palette = plt.cm.gray.with_extremes(over="r", under="g", bad="b")
// Alternatively, we could use
// palette.set_bad(alpha = 0.0)
// to make the bad region transparent. This is the default.
// If you comment out all the palette.set* lines, you will see
