title: Diagonalize symbolic matrix
body: <p>I need to diagonalize a symbolic matrix with python. In Mathematica it can be done easily, but when using the module <code>numpy.linalg</code> I get problems.</p>
  
  <p>For concreteness, consider the matrix</p>
  
  <pre><code>[[2, x], [x, 3]]
  </code></pre>
  
  <p>where <code>x</code> is a symbolic variable. I guess I get problems because the numpy package is provided for numerical computations, not symbolic, but I cannot find how to do it with sympy.</p>