function [new_X] = range_trans(X,subtract_min)
%Reshape the data points using a range shortening transformation
% Inputs:
%	X: input data
%       subtract_min: option to subtract the minimum value or not from each column 
%
% Outputs
%	new_X: each column
%--

inX = min(X,[],1); 
axX = max(X,[],1); 
[n,p] = size(X); 

denom = repmat( axX-inX, n, 1 ); 

if( nargin>1 )
  new_X = ( X - repmat(inX,n,1) ) ./ denom;
else
  new_X = X ./ denom;
end