How to place multiple colorbars next to each other in the same axis automatically
I have a plot (example here below) where I need to put multiple colorbars in the same axis
To do that at the moment I have to create a new axis for every colorbar with values defined manually like so
x_cbar_0, y_cbar_0, x_cbar_size, y_cbar_size = 0.18, 0.05, 0.3, 0.02
x_cbar2_0, y_cbar2_0, x_cbar2_size, y_cbar2_size = 0.55, 0.05, 0.3, 0.02
ax_cbar = plt.gcf().add_axes([x_cbar_0, y_cbar_0, x_cbar_size, y_cbar_size])
ax_cbar_2 = plt.gcf().add_axes([x_cbar2_0, y_cbar2_0, x_cbar2_size, y_cbar2_size])
cbar_snow = plt.gcf().colorbar(cs_snow, cax=ax_cbar, orientation='horizontal',
label='Snow')
cbar_rain = plt.gcf().colorbar(cs_rain, cax=ax_cbar_2, orientation='horizontal',
label='Rain')
This is not really a portable solution as when something is changing, for example the map projection, the plot is slightly resized and I have to tune these numbers to manually place the colorbars without overlapping.
Isn't there a way to automatically create a new axis with the same width of the figure (I believe mpl_toolkits.axes_grid1.axes_divider should do that) and then split it into an arbitrary number of sub-axes which can then be used to place the colorbars?
As @Mr. T said above, a gridspec is a pretty good way. You may want to nest gridspecs for more complicated layouts, but:
import matplotlib.pyplot as plt
import numpy as np
fig = plt.figure(constrained_layout=True)
gs = fig.add_gridspec(2, 3, height_ratios=[1, 0.05], width_ratios=[1, 0.2, 1])
ax = fig.add_subplot(gs[0, :])
pc1 = ax.pcolormesh(np.random.randn(20, 20), cmap='viridis')
pc2 = ax.pcolormesh(np.random.randn(20, 20), cmap='RdBu_r')
cax1 = fig.add_subplot(gs[1, 0])
fig.colorbar(pc1, cax=cax1, orientation='horizontal')
cax2 = fig.add_subplot(gs[1, -1])
fig.colorbar(pc2, cax=cax2, orientation='horizontal', extend='max')
plt.show()
