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% 
% function reduce(roriginal,cs)
%
% makoto nakajima, October 11,1999
%
% This routine reduce (n x n) matrix rm into (n-1x n-1) matrix rnew
% using linear equation represented by cs
%
% This program is translated from GAUSS program of Gary Hansen
%
% roriginal = (n x n) matrix to be reduced by one row and column
% cs = vector of parameters of a linear equation 
% x(n)=cs*(x(1), x(2), ... ,x(n-1))
%
% locally use : n,ccs
% inputs :roriginal,cs
% output : rnew
%
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function[rnew]=reduce(roriginal,cs) 

n=length(roriginal); 

ccs=[ eye(n-1) ; cs ]; 

rnew=ccs'*roriginal*ccs;