title: Pythonic way to update a single element of a numpy matrix?
body: <p>Say I have a function call <code>f(m1)</code> where <code>m1</code> is a numpy matrix. Now, I would like to call <code>f</code> on a matrix which is almost identical to <code>m1</code>:</p>
  
  <pre><code>m2 = m1.copy()
  m2[ 2, 7 ] = 43 # or m2[ 2, 7 ] += 43
  f(m2)
  </code></pre>
  
  <p>Is there an elegant <code>f( ... )</code> one-liner to do that?</p>