title: how to plot accuracy over number of training sample using keras?
body: <p>I have seen and used plots to measure the performance ( ie: accuracy, etc. ) of a model over epochs, but i have also seen certain papers discussing the progress of accuracy performance over the number of training samples. 
  How should i proceed to produce such graph using keras or other common deep learning libraries?</p>
  
  <p>Is this a way to fairly compare several models over the number of training samples they would need to reach satisfactory performance ? </p>