title: python matplotlib plot sparse matrix pattern
body: <p>Given a sparse binary matrix A (csr, coo, whatever) I want to make a plot such that I can see the position (i,j) = white in the figure if A(i,j) = 1, and (i,j) = black if A(i,j) = 0;</p>
  
  <p>For a dense numpy array, matshow will do the job. However, the dimension of my sparse matrix (say 100000 x 1000000) is to big to be converted to a dense array. I wonder how could I plot the pattern in my sparse matrix.</p>
  
  <p>Thanks</p>