function r = ranktrf(x)
%RANKTRF  Rank transformation of data material.
%
%	  r = ranktrf(x)
%
%         Replaces the data vector  x  and gives rank numbers.
%	  In case  x  is a matrix every column is rank transformed.

%       GPL Copyright (c) Anders Holtsberg, 1998

tr = 0;
if size(x,1) == 1
   x = x';
   tr = 1;
end

n = size(x,1);
v = (1:n)';

[dummy, i] = sort(x);
[dummy, r1] = sort(i);
[dummy, i] = sort(flipud(x));
[dummy, r2] = sort(i);
r = (r1+flipud(r2))/2;

if tr
   r = r';
end