Eigenvalue and Matrix array
<p>I'm trying to compute <code>eigenvalue</code> for <code>matrix[7][7]</code>, and my code is:</p>

<pre><code>for (i = 0; i&lt;M; i++)               //matrix + identity
      {
        for (j = 0; j&lt;M; j++)
        {

            MI[i][j] = MX[i][j] + a[i][j];
            cout &lt;&lt; setw(7) &lt;&lt; MI[i][j] &lt;&lt; " ";

            MatrixXd W;
            W = MI[i][j];
            SelfAdjointEigenSolver &lt;MatrixXd&gt; eigensolver (W);
            cout &lt;&lt; "The eigenvalues of A are:\n" &lt;&lt; eigensolver.eigenvalues() &lt;&lt; endl;
        }
        cout &lt;&lt; endl;

    }
</code></pre>

<p>My question is am I doing it right calling my matrix by define as <code>matrixXd W</code>?</p>

<p>I end up with an error in line <code>W = MI[i][j]</code>:</p>

<blockquote>
  <p>no operand "=" matches this operand &amp; oeprand types are :MatrixXd=double</p>
</blockquote>