[FIXED] Create a grayscale colorbar for each subplot in python

Issue

I have two polygon patch plots with shading in grayscale, with each patch added to an axis. and I would like to add a colorbar underneath each subplot. I'm using

import matplotlib.patches as mpatches
import matplotlib.pyplot as plt 

poly=mpatches.Polygon(verts,color=rgb,ec='black') #create patch 
ax.add_patch(poly) #add patch to axis 

plt.set_cmap('gray') #grayscale colormap 

        #verts,rgb input created in above lines of code

The colorbars should be in grayscale and have range [0,1], with 0 being black, 0.5 marked, and 1 being white. im using subplot(121) and (122). Thanks in advance.

Solution

To use colorbars you have to have some sort of ScalarMappable instance (this is used for imshow, scatter, etc.):

mappable = plt.cm.ScalarMappable(cmap='gray')
# the mappable usually contains an array of data, here we can
# use that to set the limits
mappable.set_array([0,1])   
ax.colorbar(mappable)

Answered By - hitzg