Download All

Code covered by the BSD License  

Highlights from
Estimating the number of clusters via System Evolution

from Estimating the number of clusters via System Evolution by Kaijun Wang
estimate number of clusters for far clusters, small-larger clusters, slightly overlapping clusters

nearest(z,xi); 
function [zj,j,d] = nearest(z,xi);
% NEAREST: return the vector zj in z that is nearest to xi
% [zj,j,d] = nearest(z,xi)
%	z  - d*J vectors that need to be compared to xi
%	xi - the vector that wants to be matched up with zj
%	zj - the nearest vector to xi in z
%	j  - the index of zj in z
%	d  - the minimum distance

% Copyright (c) 1995 Frank Dellaert
% All rights Reserved

[r,J] = size(z);
if size(xi) ~= r, error('NEAREST: z and x need to be of same dimensions!'); end

zj = z(:,1); j = 1;
if (J==1), return, end

d = norm(zj-xi);
for i=2:J,
  zi = z(:,i);
  distance = norm(zi-xi);
  if (distance<d), zj=zi; j=i; d=distance; end
end

Contact us at files@mathworks.com