title: Getting N random numbers whose sum is M
body: <p>I want to get N random numbers whose sum is a value.</p>
  
  <p>For example, let's suppose I want 5 random numbers that sum to 1.</p>
  
  <p>Then, a valid possibility is:</p>
  
  <pre><code>0.2 0.2 0.2 0.2 0.2
  </code></pre>
  
  <p>Another possibility is:</p>
  
  <pre><code>0.8 0.1 0.03 0.03 0.04
  </code></pre>
  
  <p>And so on. I need this for the creation of a matrix of belongings for Fuzzy C-means.</p>