title: How do I compress data points in time-series using MATLAB?
body: <p>I'm looking for some suggestions on how to compress time-series data in MATLAB.</p>
  
  <p>I have some data sets of pupil size, which were gathered during 1 sec with 25,000 points for each trial(I'm still not sure whether it is proper to call the data 'timeseries'). What I'd like to do from now is to compare them with another data, and I need to compress the number of points into about 10,000 or less, minimizing loss of the information. Are there any ways to do it?</p>
  
  <p>I've tried to search how to do this, but all that I could find out was the way to smooth the data or to compress digital images, which were already done or not useful to me.</p>
  
  <p>• The data sets simply consist of pupil diameter, changing as time goes. For each trial, 25,000 points of data were gathered during 1 sec, that means 1 point denotes the pupil diameter measured for 0.04msec. What I want to do is just to adjust this data into 0.1 msec/point; however, I'm not sure whether I can apply techniques like FFT in this case because it is the first time that I handle this kind of data. I appreciate your advices again.</p>