problem with png image

Hi list.
I generate some png images using matplotlib, and get very different
results depending on figuresize

···

__________________________________________________________________
  from pylab import figure, plot
  import pylab as plt
  import numpy as np
  figure()
  plt.subplot(2,1,1)
  plot(np.random.rand(10),'o')
  plt.subplot(2,1,2)
  plot(np.random.rand(10),'o')
  pic_name='fit_rates1.png'
  path_name='/home/petro/tmp/'
  plt.savefig(path_name + pic_name)
__________________________________________________________________

the code above generates the following image:
https://lh3.googleusercontent.com/-107Ducz_CA0/UDShKMtejtI/AAAAAAAACls/YOeahS3tQA8/s400/fit_rates1.png

now if I increase a figure size parameter:
__________________________________________________________________
  from pylab import figure, plot
  import pylab as plt
  import numpy as np
  plt.ioff()
  from matplotlib import rcParams
  golden_mean = (np.sqrt(5)-1.0)/2.0 # Aesthetic ratio
  fig_width = 5.6 # width in inches
  fig_height = fig_width*golden_mean # height in inches
  rcParams['figure.figsize']=fig_width, fig_height*3
  figure()
  plt.subplot(2,1,1)
  plot(np.random.rand(10),'o')
  plt.subplot(2,1,2)
  plot(np.random.rand(10),'o')
  pic_name='fit_rates2.png'
  path_name='/home/petro/tmp/'
  plt.savefig(path_name + pic_name)
  
__________________________________________________________________
the result looks strange like this:
https://lh5.googleusercontent.com/-4GRQxuRFvh4/UDSiRrNy59I/AAAAAAAACmA/Kho3prHFpUU/s640/fit_rates2.png
Has anyone experienced behaviour like this?
Thanks.
Petro

What backend are you using?

print plt.get_backend()

···

On Wed, Aug 22, 2012 at 11:28:54AM +0200, Petro wrote:

Hi list.
I generate some png images using matplotlib, and get very different
results depending on figuresize
__________________________________________________________________
  from pylab import figure, plot
  import pylab as plt
  import numpy as np
  figure()
  plt.subplot(2,1,1)
  plot(np.random.rand(10),'o')
  plt.subplot(2,1,2)
  plot(np.random.rand(10),'o')
  pic_name='fit_rates1.png'
  path_name='/home/petro/tmp/'
  plt.savefig(path_name + pic_name)
__________________________________________________________________

the code above generates the following image:
https://lh3.googleusercontent.com/-107Ducz_CA0/UDShKMtejtI/AAAAAAAACls/YOeahS3tQA8/s400/fit_rates1.png

now if I increase a figure size parameter:
__________________________________________________________________
  from pylab import figure, plot
  import pylab as plt
  import numpy as np
  plt.ioff()
  from matplotlib import rcParams
  golden_mean = (np.sqrt(5)-1.0)/2.0 # Aesthetic ratio
  fig_width = 5.6 # width in inches
  fig_height = fig_width*golden_mean # height in inches
  rcParams['figure.figsize']=fig_width, fig_height*3
  figure()
  plt.subplot(2,1,1)
  plot(np.random.rand(10),'o')
  plt.subplot(2,1,2)
  plot(np.random.rand(10),'o')
  pic_name='fit_rates2.png'
  path_name='/home/petro/tmp/'
  plt.savefig(path_name + pic_name)
  
--
Damon McDougall
http://www.damon-is-a-geek.com
B2.39
Mathematics Institute
University of Warwick
Coventry
West Midlands
CV4 7AL
United Kingdom