How do you change the size of figures drawn with matplotlib?

How do you change the size of figure drawn with matplotlib?

From stackoverflow

• The following seems to work:

  from pylab import *
  rcParams['figure.figsize'] = 5, 10
  

  This makes the figure's width 5 inches, and its height 10 inches.

  The Figure class then uses this as the default value for one of its arguments.

  ---

  Does anyone know more direct mechanisms?

• The first link in Google for 'matplotlib figure size' is AdjustingImageSize (google cache of the page: http://74.125.77.132/search?q=cache:http://www.scipy.org/Cookbook/Matplotlib/AdjustingImageSize).

  Here's a test script from the above page. It creates test[1-3].png files of different sizes of the same image:

  #!/usr/bin/env python
  """
  This is a small demo file that helps teach how to adjust figure sizes
  for matplotlib
  
  """
  
  import matplotlib
  print "using MPL version:", matplotlib.__version__
  matplotlib.use("WXAgg") # do this before pylab so you don'tget the default back end.
  
  import pylab
  import matplotlib.numerix as N
  
  # Generate and plot some simple data:
  x = N.arange(0, 2*N.pi, 0.1)
  y = N.sin(x)
  
  pylab.plot(x,y)
  F = pylab.gcf()
  
  # Now check everything with the defaults:
  DPI = F.get_dpi()
  print "DPI:", DPI
  DefaultSize = F.get_size_inches()
  print "Default size in Inches", DefaultSize
  print "Which should result in a %i x %i Image"%(DPI*DefaultSize[0], DPI*DefaultSize[1])
  # the default is 100dpi for savefig:
  F.savefig("test1.png")
  # this gives me a 797 x 566 pixel image, which is about 100 DPI
  
  # Now make the image twice as big, while keeping the fonts and all the
  # same size
  F.set_size_inches( (DefaultSize[0]*2, DefaultSize[1]*2) )
  Size = F.get_size_inches()
  print "Size in Inches", Size
  F.savefig("test2.png")
  # this results in a 1595x1132 image
  
  # Now make the image twice as big, making all the fonts and lines
  # bigger too.
  
  F.set_size_inches( DefaultSize )# resetthe size
  Size = F.get_size_inches()
  print "Size in Inches", Size
  F.savefig("test3.png", dpi = (200)) # change the dpi
  # this also results in a 1595x1132 image, but the fonts are larger.
  

  Output:

  using MPL version: 0.98.1
  DPI: 80
  Default size in Inches [ 8.  6.]
  Which should result in a 640 x 480 Image
  Size in Inches [ 16.  12.]
  Size in Inches [ 16.  12.]
  

  Two notes:

  1. The module comments and the actual output differ.

  2. This answer allows easily to combine all three images in one image file to see the difference in sizes.

• Hmm, I appear to be unable to use google...

• help(figure) tells you the call signature:

  figure(num=None, figsize=(8, 6), dpi=80, facecolor='w', edgecolor='k')
  

  So figure(figsize=(1,1)) creates an inch-by-inch image, which will be 80-by-80 pixels unless you also give a different dpi argument.