title: find time shift between two similar waveforms
body: <p>I have to compare two time-vs-voltage waveforms. Because of the peculiarity of the sources of these waveforms, one of them can be a time shifted version of the other. </p>
  
  <p>How can i find whether there is a time shift? and if yes, how much is it.</p>
  
  <p>I am doing this in Python and wish to use numpy/scipy libraries.</p>