title: Submatrix with stride in Eigen Library
body: <p>I'm new to Eigen and I would like to create 10 mxn matrices.
  For some reasons I do it with the following method:</p>
  
  <pre><code>Matrix&lt;double, m, n*10&gt;
  </code></pre>
  
  <p>Which It seems that the memory allocation will be similar to the following:</p>
  
  <pre><code> _______________________________________________________________
  |M1(1,1)|M2(1,1)|...|M10(1,1)|.....|M1(1,n)|M2(1,n)|...|M10(1,n)|
  |  . .                                                          |
  |  .                                                            |
  </code></pre>
  
  <p>Now how it possible to create a reference matrix (means by reference and without copying data) to each of this 10 matrices?</p>