pyplot/matplotlib Bar chart with fill color depending on value

Question

I want to produce in python with matplotlib/pyplot

• a bar chart with a fill depending on the value.
• legend color bar

while

Answer 1

You can use Normalize and ScalarMappable without plotting a scatter. For example:

import matplotlib mpl
import matplotlib.pyplot as plt
from matplotlib import cm

f,(ax1,ax2) = plt.subplots(2)

#ax1 --> plot here your bar chart

norm = mpl.colors.Normalize(vmin=0, vmax=1)

mpl.colorbar.ColorbarBase(ax2, cmap=cm.RdBu,
                                norm=norm,
                                orientation='horizontal')

Finally, add the desired format to the colorbar.