title: What's the best method to compare original trajectory with two compressed trajectory
body: <p>Suppose to have a GPS trajectory - i.e.: a series of spatio-temporal coords, every coord is a (x,y,t) information, where x is longitude, y is latitude and t is the time stamp. 
  Suppose each trajectory identified by 1000 (x,y) points, a compressed trajectory is trajectory with fewer points than the original, for instance 300 points. A compression algorithm (Douglas-Peucker, Bellman, etc) decide what points will be in compressed trajectory and what point will be discarded.</p>
  
  <p>Each algorithm make his own choice. Better algorithms choice the points not only by spatial characteristics (x, y) but using spatio-temporal characteristics (x,y,t).</p>
  
  <p>Now I need a way to compare two compressed trajectories against the original to understand what compression algorithm better reduce a spatio-temporal (temporal component is really important) trajectory.</p>
  
  <p>I've thinked of DTW algorithm to check trajectory similarity, but this probably don't care about temporal component. What algorithm can I use to make this control?</p>