import mpl_toolkits.axes_grid1.axes_size as Size
from mpl_toolkits.axes_grid1 import Divider
import matplotlib.pyplot as plt

fig1 = plt.figure(1, (5.5, 4.))

# the rect parameter will be ignore as we will set axes_locator
rect = (0.1, 0.1, 0.8, 0.8)
ax = [fig1.add_axes(rect, label="%d"%i) for i in range(4)]

horiz = [Size.Scaled(1.5), Size.Fixed(.5), Size.Scaled(1.),
         Size.Scaled(.5)]

vert = [Size.Scaled(1.), Size.Fixed(.5), Size.Scaled(1.5)]

# divide the axes rectangle into grid whose size is specified by horiz * vert
divider = Divider(fig1, rect, horiz, vert, aspect=False)

ax[0].set_axes_locator(divider.new_locator(nx=0, ny=0))
ax[1].set_axes_locator(divider.new_locator(nx=0, ny=2))
ax[2].set_axes_locator(divider.new_locator(nx=2, ny=2))
ax[3].set_axes_locator(divider.new_locator(nx=2, nx1=4, ny=0))

for ax1 in ax:
    plt.setp(ax1.get_xticklabels()+ax1.get_yticklabels(),
             visible=False)

plt.draw()
plt.show()