Changing matplotlib subplot size/position after axes creation

Question

Is it possible to set the size/position of a matplotlib subplot after the axes are created? I know that I can do:

import matplotlib.pyplot as plt

ax = plt.subp         


        

Answer 1

You can avoid ax.set_position() by using fig.tight_layout() instead which recalculates the new gridspec:

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec

# create the first axes without knowing of further subplot creation
fig, ax = plt.subplots()
ax.plot(range(5), 'o-')

# now update the existing gridspec ...
gs = gridspec.GridSpec(3, 1)
ax.set_subplotspec(gs[0:2])
# ... and recalculate the positions
fig.tight_layout()

# add a new subplot
fig.add_subplot(gs[2])
fig.tight_layout()
plt.show()

Answer 2

You can create a figure with one subplot that spans two rows and one subplot that spans one row using the rowspan argument to subplot2grid:

import matplotlib.pyplot as plt

fig = plt.figure()
ax1 = plt.subplot2grid((3,1), (0,0), rowspan=2)
ax2 = plt.subplot2grid((3,1), (2,0))
plt.show()

If you want to change the subplot size and position after it's been created you can use the set_position method.

ax1.set_position([0.1,0.1, 0.5, 0.5])

Bu you don't need this to create the figure you described.

Answer 3

Thanks to Molly pointing me in the right direction, I have a solution:

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec

fig = plt.figure()

ax = fig.add_subplot(111)

gs = gridspec.GridSpec(3,1)
ax.set_position(gs[0:2].get_position(fig))
ax.set_subplotspec(gs[0:2])              # only necessary if using tight_layout()

fig.add_subplot(gs[2])

fig.tight_layout()                       # not strictly part of the question

plt.show()