title: Convert Matlab timestamp data to seconds (HH:MM:SS:TTT -> seconds)
body: <p>My data (cell) in Matlab looks like this:</p>
  
  <pre><code>00.00.00.515
  00.00.00.671
  00.00.00.828
  00.00.00.984
  00.00.01.140
  etc.
  </code></pre>
  
  <p>This is the time stamp: HH:MM:SS:TTT, the T stands for thousandth (=milliseconds). The milliseconds are important because the step size is small. How to convert this data (cell) to data Matlab can handle (double)?
  So the data will be as follow:</p>
  
  <pre><code>0.515
  0.671
  0.828
  0.984
  1.140
  etc.
  </code></pre>
  
  <p>The minutes and hours should be converted to seconds so it is easy to calculate the total time of the data or the average stepsize. So:</p>
  
  <pre><code>01.30.00.000    
  </code></pre>
  
  <p>will be:</p>
  
  <pre><code>5400.000
  </code></pre>
  
  <p>seconds</p>
  
  <p>Thanks!</p>