On Tue, Feb 15, 2011 at 11:07 PM, Victor Hooi <victorhooi@yahoo.com> wrote:

Is there an easy way to colour-code a Matplotlib histogram with a single set of data?

So for example, you'd have a bell-shaped histogram, and the middle 50% might be green, the regions 20% to the left and right of that might be yellow, and the 5% either side beyond that could be red.

I couldn't seem to find anything in the Matplotlib options for this - any suggestions?


Sure, check out the following:

import matplotlib.pyplot as plt
import numpy as np

xs = np.arange(20)
ys = np.random.rand(20)
cs = (['y'] * round(0.25 * len(xs))) + (['g'] * round(0.5 * len(xs))) + (['y'] * round(0.25 * len(xs)))

plt.bar(xs, ys, color=cs)

Admittedly, this isn't using matplotlib's hist() function because it only allows for one color per dataset.  However, you can use numpy's histogram function to get the bins and counts yourself, and then use bar() to make the bars.  bar() will allow you to color the bars individually.

I hope this helps!
Ben Root