title: Convert output from symbolic math (sym) to double
body: <p>I have a 2x2 matrix created with a symbol in matlab. Because of the symbol (x) all values are converted to integers such as </p>
  
  <pre><code>T14 =
     [ 1, - x - 8070491064644575/4503599627370496]
     [ 0,                                       1]
  </code></pre>
  
  <p>instead of </p>
  
  <pre><code>T14 =
     [ 1, - x - 1.7920]
     [ 0,                                       1]
  </code></pre>
  
  <p>The final matrix is created with </p>
  
  <pre><code>M = B16*T15*B15*T14*B14*T13*B13*T12*B12*T11*B11*T10
  </code></pre>
  
  <p>and contains mostly values like 
             <code>5098902830068945997216661558291421977734221147306628926962736786585701268374390522728433444885024747513/17917957937422433684459538244547554224973163977877196279199912807710334969441287563047019946172856926208</code></p>
  
  <p>I now want to convert all integer values to double values while keeping the symbol x. A simple <code>double</code> fails because <code>M</code> contains a symbol. How could I convert the whole matrix to a matlab like matrix with doubles?</p>