mfbox_voronoimap.m

toolbox for spm 5 for data, model free analysis

function [s,err,dis]=mfbox_voronoimap(c,d)
% usage: [s,err,dis]=mfbox_voronoimap(c,d)
%
% Copyright by Peter Gruber
% Signal Processing & Information Theory group
% Institute of Biophysics, University of Regensburg, Germany
% Homepage: http://research.fabian.theis.name
%           http://www-aglang.uni-regensburg.de
%
% This file is free software, subject to the 
% GNU GENERAL PUBLIC LICENSE, see gpl.txt

error(nargchk(2,2,nargin))     % check no. of input args

s = zeros(1,size(c,1));
r = zeros(1,size(c,1));
steps = floor(10000000/size(d,1));
for i=1:steps:size(c,1)
    l = i:min(i+steps-1,size(c,1));
    [ri,si] = min(repmat(sum(d.^2,2),1,length(l))-2*d*c(l,:)');
    s(l) = si;
    r(l) = ri;
end
dis = {};
if (nargout>1)
    err = size(1,size(d,1));
    for i=1:size(d,1)
        v = find(s==i);
        e = r(v)+sum(c(v,:).^2,2)';
        if (nargout>2), dis{i} = e; end
        if (length(v)>0)
            err(i) = sum(e)/sum(v);
        else
            err(i) = 0;
        end
    end
end
 
return