function [xj,I] = cluster(x,c,j);% CLUSTER : return the matrix of samples in cluster j according to c% [xj,I] = cluster(x,c,j)%	x  - data%	c  - categories%	j  - cluster identity%	xj - x samples in cluster j%	I  - indices of these samples in x/c% Copyright (c) 1995-1996 Frank Dellaert% All rights Reserved[dx,nx] = size(x);[dc,nc] = size(c);if (nc~=nx) error('cluster: x and c must have same number of columns'); endif (dc~=1) error('cluster: c must be row vector'); endI = find(c==j);xj = x(:,I);