title: How to create a heat map in python that ranges from green to red?
body: <p>I'm trying to plot log ratios from the range -3 to 3 and want negative ratios to be green and positive to be red, with a log ratio of 0 (center) to be white in color. None of the pre-existing color schemes in matplotlib provide this option, and I haven't been able to figure out how to output a nice gradient manually.</p>