Shrink colorbar with AxesGrid and basemap


I am using Basemap to create a grid of 12 images of the world (months of the year), but I want to have a single colorbar underneath the plots. I have managed this successfully but I can’t manage to shrink the colorbar width. Currently it extends the entire width of the plotting window, whereas I’d prefer it to be say extend 80% of the plotting window. I’ve tried combining what I have with the shrink argument to colorbar but this doesn’t work. Does anyone know how I can achieve this?


import numpy as np

import matplotlib.pyplot as plt

import sys

import matplotlib.colors as colors

from mpl_toolkits.basemap import Basemap

from mpl_toolkits.axes_grid1 import AxesGrid

months = [‘Jan’,‘Feb’,‘Mar’,‘Apr’,‘May’,‘Jun’,‘Jul’,‘Aug’,‘Sep’,‘Oct’,\


fig = plt.figure(figsize=(14, 10))

grid = AxesGrid(fig, [0.05,0.05,0.9,0.9], nrows_ncols=(4,3), axes_pad=0.1,

cbar_mode=‘single’, cbar_pad=0.4, cbar_size=“7%”,

cbar_location=‘bottom’, share_all=True)

m = Basemap(projection=‘cyl’, llcrnrlon=-179.5, llcrnrlat=-59.5, \

urcrnrlon=179.5, urcrnrlat=89.5, resolution=‘c’)

for i, month in enumerate(months):

ax = grid[i] = ax

m.drawcoastlines(linewidth=0.1, color=‘k’)

m.drawcountries(linewidth=0.1, color=‘k’)

if i == 0 or i == 3 or i == 6 or i == 9:


labels=[1,0,0,1], fontsize=10, rotation=0,

linewidth=0.2, dashes=[2,2])



labels=[0,0,0,0], fontsize=10, rotation=0,

linewidth=0.2, dashes=[2,2])

if i >= 9:


labels=[0,0,0,1], fontsize=10, rotation=00,

linewidth=0.2, dashes=[2,2])



labels=[0,0,0,0], fontsize=10, rotation=00,

linewidth=0.2, dashes=[2,2])

diff = np.random.rand(150,360)

image = m.imshow(diff,, interpolation=‘nearest’)

textstr=’%s’ % (month)

props = dict(boxstyle=‘round’, facecolor=‘white’, alpha=1.0, ec=“white”)

ax.text(0.03, 0.1, textstr, transform=ax.transAxes, fontsize=8,

verticalalignment=‘top’, bbox=props)

cbar = fig.colorbar(image, cax=grid.cbar_axes[0], orientation=‘horizontal’)



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