title: How to normalize matplotlib colormap on Natural Logarithm scale
body: <p>I would like to use imshow for plotting a matrix whose elements are in [1, 64]. To normalise the colormap, I could only find "LogNorm", however, I need something like "LnNorm", normalising the matrix elements on natural logarithm scale. Is there a way that I could do this?</p>
  
  <p>Thanks for your help.</p>