text: function y = rescale(x,a,b)
  
  % rescale - rescale data in [a,b]
  %
  %   y = rescale(x,a,b);
  %
  %   Copyright (c) 2004 Gabriel Peyr?
  
  if nargin<2
      a = 0;
  end
  if nargin<3
      b = 1;
  end
  
  m = min(x(:));
  M = max(x(:));
  
  if M-m<eps
      y = x;
  else
      y = (b-a) * (x-m)/(M-m) + a;
  end
  
  
  