title: Convert array to python scalar
body: <p>I need big help, please check out this code:</p>
  
  <pre><code>import.math
  
  dose =20.0
  a = [[[2,3,4],[5,8,9],[12,56,32]]
       [[25,36,45][21,65,987][21,58,89]]
       [[78,21,98],[54,36,78],[23,12,36]]]
  PAC = math.exp(-dose*a)
  </code></pre>
  
  <p>this what I would like to do. However the error I am getting is </p>
  
  <pre><code>TypeError: only length-1 arrays can be converted to Python scalars
  </code></pre>