I use a trick to draw a colorbar whose height matches the master axes. The code is like
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable
import numpy as np
ax = plt.subplot(111)
im = ax.imshow(np.arange(100).reshape((10,10)))
# create an axes on the right side of ax. The width of cax will be 5%
# of ax and the padding between cax and ax will be fixed at 0.05 inch.
divider = make_axes_locatable(ax)
cax = divider.append_axes("right", size="5%", pad=0.05)
plt.colorbar(im, cax=cax)
This trick works good. However, since a new axis is appended, the current instance of the figure becomes cax - the appended axis. As a result, if one performs operations like
plt.text(0,0,'whatever')
the text will be drawn on cax instead of ax - the axis to which im belongs.
Meanwhile, gcf().axes shows both axes.
My question is: How to make the current axis instance (returned by gca()) the original axis to which im belongs.
Use plt.sca(ax) to set the current axes, where ax is the Axes object you'd like to become active.