Changing size of MatPlotLib figure with PS backend - matplotlib

Question

I am generating a figure using the PS backend:
import matplotlib
matplotlib.use('ps')
from matplotlib import pyplot as plt
plt.plot((1, 2))
I would like to save the figure:
plt.savefig('test.eps', format='eps', bbox_inches='tight', pad_inches=1.0)
Incidentally, I will make a PNG out of it later (in case it turns out to be relevant to the solution):
gs -q -dSAFER -dBATCH -dNOPAUSE -dUseTrimBox -dEPSCrop -sDEVICE=pngalpha -sOutputFile=test.png test.eps
The result is (PNG viewed in eog):
I would like to change the size of the EPS or the PNG figure, but adding a dpi kwarg to savefig does not change the output. Calling plt.gcf().set_size_inches(10, 10) does nothing as well. How do I make my EPS or PNG file have a higher resolution?
This answer is relevant in that it hints that setting dpi for the ps backend may not be the way to go.
Update
For clarification, it is necessary for me to use the PS backend. At the moment, it is the only one that correctly renders LaTeX colored strings. PGF may or may not do what I want, but I do not have time to research its quirks in depth. I was able to get a hacky solution by adding a -r... argument to gs, but would prefer to control everything from MatPlotLib.

Answer 1

If you create the figure with plt.figure first, you can give the figsize-kwarg. An example:
import matplotlib.pyplot as plt
fig = plt.figure(figsize=(10, 1)) # figsize in inches
fig.show() # if running in ipython
# plt.show() # if running as a script with "python script_name.py"
To save with a specific dpi, it should be enough with mentioned dpi-kwarg to the figures savefig-method, i.e.
fig.savefig(..., dpi=300)
Note that if you work with plt to save the figure or to plot, it will always work with the active figure, which might not be the figure you expect if you happen to have several of them opened.
UPDATE
1)
Based on the comment by Mad Physicist, the dpi-kwarg apperently does not work with the PS backend. I do not know why.