Removing axes and lining up a subplot

Question

I have produced a graph with two subplots and am trying to add a histogram to the end of the residuals plot but am unable to remove the x-axis of the histogram plot and get it to line up with the end of the residual plot.

Here is a copy of my current code:

#graph with histogram and std error plot thing
fig1 = plt.figure(figsize =(9.6,7.2))
ax = fig1.add_axes((0.2,0.4,.75,.6))
ax.errorbar(xval, yval*1000, yerr=yerr*1000, xerr=xerr, marker='x', linestyle='None')

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
ax.yaxis.set_ticks_position('left')
ax.xaxis.set_ticks_position('bottom')

# Axis labels
plt.xlabel('Height (m)', fontsize = 12)
plt.ylabel('dM/dt (g $s^{-1}$) × $10^{3}$', fontsize = 12)


# Generate best fit line using model function and best fit parameters, and add to plot
fit_line=model_funct(xval, [a_soln, b_soln])
plt.plot(xval, fit_line*1000)

# Set suitable axis limits: you will probably need to change these...
#pyplot.xlim(-1, 61)
#pyplot.ylim(65, 105)
# pyplot.show()


ax2 = fig1.add_axes((0.2,0.2,.75,.2))    #start frame1 at 0.2, 0.4 
plt.xlabel("Height of Water (m)", fontsize = 12)
plt.ylabel("Normalised\nResiduals", fontsize = 12)    #\n is used to start a new line
ax2.plot(h,normalised_residuals,"x", color = "green")
plt.axhline(0, linewidth=1, linestyle="--", color="black")

plt.savefig("Final Graph with added parts.png", dpi = 500)

ax2.axhspan(ymin = -np.std(normalised_residuals), ymax = np.std(normalised_residuals), color = 'gray', alpha =0.5)


ax3 = fig1.add_axes((1,0.2,0.2,0.2))

ax3.hist(normalised_residuals, bins=8, orientation="horizontal")

ax3.spines['right'].set_visible(False)
ax3.spines['top'].set_visible(False)
ax3.spines['left'].set_visible(False)


ax3.yaxis.set_ticks_position('left')
ax3.xaxis.set_ticks_position('bottom')

and here is a picture of my graph currently:

Answer 1

An example with random data. Using tick_params and manually setting both ylim and the histogram range , did the trick.

import matplotlib.pyplot as plt
import numpy as np

fig1 = plt.figure(figsize=(20, 15))
ax = fig1.add_axes((0.2, 0.4, .75, .6))
ax2 = fig1.add_axes((0.2, 0.2, .75, .2))
ax3 = fig1.add_axes((.95, 0.2, 0.2, 0.2))

xval = (np.linspace(0.02, 0.15, 20)
        + (np.random.default_rng(0).random(20) - 0.5) / 30)
yval = 2 * xval + 0.08
xerr = (np.random.default_rng(0).random(20) * 2 - 1) / 60
yerr = (np.random.default_rng(1).random(20) * 2 - 1) / 60

ax.errorbar(xval, yval, yerr=yerr, xerr=xerr, marker='x', linestyle='None')
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
ax.tick_params(labelbottom=False)
ax.set_xlabel('Height (m)', fontsize=12)
ax.set_ylabel('dM/dt (g $s^{-1}$) × $10^{3}$', fontsize=12)

ax2.plot(xval, xerr, 'x', color='green')
ax2.axhline(0, linewidth=1, linestyle='--', color='black')
ax2.axhspan(ymin=-np.std(xerr), ymax=np.std(xerr), color='gray', alpha=0.5)
ax2.set_xlabel('Height of Water (m)', fontsize=12)
ax2.set_ylabel('Normalised\nResiduals', fontsize=12)
resLim = ax2.get_ylim()

ax3.hist(xerr, bins=8, orientation='horizontal', range=resLim, rwidth=0.9)
ax3.spines['right'].set_visible(False)
ax3.spines['top'].set_visible(False)
ax3.spines['left'].set_visible(False)
ax3.spines['bottom'].set_visible(False)
ax3.tick_params(labelbottom=False, labelleft=False, bottom=False, left=False)
ax3.set_ylim(resLim)
fig1.savefig('so.png', bbox_inches='tight')