title: BOW using Matlab in action recognition
body: <p>My question is really simple but it is very confused to me :(</p>
  
  <p>I am doing action recognition process using Matlab. I have 10 different actions, each action has 20 different videos, each video concludes descriptor with 500 points x 350 features (array 500x350).</p>
  
  <p>When doing the vocab of words; suppose I took first 10 videos of each action as training set, then I will have 100 videos as training, 100(500x350).</p>
  
  <p>My question, is how to consider the correspondence between training and test sets. I mean one of those:</p>
  
  <ul>
  <li>array of TRAIN is 100 cells, each cell is [500x350]double and array of TEST is [100x1] double.</li>
  <li>array of TRAIN is double, [50000x350]double and array of TEST is [50000x1] double.
  I mean I should treat each video as one instance, or each point [1x350] as instance !! I don't know what is the correct implementation.</li>
  </ul>
  
  <p>Many thanks.</p>