title: Matlab - calculating max eigenvalue of a big sparse (A'*A) matrix
body: <p>I have a big (<strong>400K*400K</strong>) sparse matrix and I need to calculate the largest eigenvalue of <strong>A'*A</strong>.</p>
  
  <p>The problem is that Matlab can't even calculate A' due to memory problems.<br>
  I also tried <code>[a,b,c] = find(A)</code> and then transpose by creating a transpose sparse matrix, but although the <code>find()</code> works, the sprase creation doesn't.</p>
  
  <p>Is there a nice solution for this? it can be either in a matlab function or in another technique to calculate the largest eigenvalue for this kind of multiplication.</p>
  
  <p>Thanks.</p>