matplotlib: Using append_axes multiple times

Question

I'm new to matplotlib, so I do not have strong enough command of the language to know if I'm going about this the right way, but I've been searching for the answer for a while now, and I just cannot find anything one way or the other on this.

I know how to use matplotlib's append_axes locator function to append histograms alongside 2D plots, e.g.:

axMain= fig1.add_subplot(111)
cax = plt.contourf(xl,y1,z1)
divider = make_axes_locatable(axMain)
axHisty = divider.append_axes("right", 1.2, pad=0.1, sharey=axMain)
axHisty.plot(x,y)

and I also know how to append a colorbar in a similar manner:

divider = make_axes_locatable(axMain)
ax_cb = divider.new_horizontal(size='5%', pad=0.3)
fig1.add_axes(ax_cb)
fig1.colorbar(cax, cax=ax_cb)

What I am not clear on is how to do both in the same subplot without the two appended figures overlapping. To be clear, I want the histogram to have the same yaxis ticks and height as the axContour, and I want the colorbar to have the same height as axContour. ImageGrid doesn't seem to be quite what I want because I do not want to fix the size of my plot. It would better for me if I could add/remove these figure "embellishments" interactively, but maybe that is not possible...Let me know!

Answer 1

You are already fixing the size of your plot with divider.append_axes("right", 1.2, pad=0.1, sharey=axMain). 1.2 is the size of the new axis. Below is a way of plotting three axes using gridspec.

import matplotlib.pyplot as plt
import numpy as np
import matplotlib.gridspec as grd
from numpy.random import rand

# add axes
fig1 = plt.figure(1)
gs = grd.GridSpec(1, 3, width_ratios=[5,1, 1], wspace=0.3)
axMain = plt.subplot(gs[0])
axHisty = plt.subplot(gs[1])
ax_cb = plt.subplot(gs[2])

# some things to plot
x = [1,2,3,4]
y = [1,2,3,4]
x1 = [1,2,3,4]
y1 = [1,2,3,4]
z1 = rand(4,4)

# make plots
h = axMain.contourf(x1,y1,z1)
axHisty.plot(x,y)
cb = plt.colorbar(h, cax = ax_cb)

plt.show()