function OUT = dat_trans(X);

%DAT_TRANS transforms data sets by taking deviations about the mean,
%and then scaling to (-1,1) by dividing each column by the maximum 
%absolute value in that column.

%INPUT: X = (nxk)-data matrix
%
%OUTPUT: OUT = (nxk) transformed matrix

%Take deviations

n = length(X) ;

u = ones(n,1) ;

XX = X - u*mean(X) ;

%Scale by max absolute values

OUT = XX./(u*max(abs(XX)));