mfbox_transform.m

toolbox for spm 5 for data, model free analysis

function V=mfbox_transform(M,dim,O)
%
% Copyright by Peter Gruber and Fabian J. Theis
% 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

V = zeros(dim);
so = size(O)';

g = mfbox_mkgrid(dim)';
%[g1,g2,g3] = ndgrid([1:dim(1)],[1:dim(2)],[1:dim(3)]);
%g = [g1(:),g2(:),g3(:)]';
if (sum(sum((M(1:3,1:3)-eye(3)).^2))<sqrt(eps) && sum(M(1:3,4).^2)<sqrt(eps))
    odim = size(O);
    mx = min(dim(1),odim(1));
    my = min(dim(2),odim(2));
    mz = min(dim(3),odim(3));
    V(1:mx,1:my,1:mz) = O(1:mx,1:my,1:mz);
end
n  = M(1:3,1:3)*g+repmat(M(1:3,4),1,size(g,2));
vn = (min(n-1,[],1)>=0)&(min(repmat(so,1,size(g,2))-n,[],1)>=0);
if (all(vn(:)))
    V = interpn(O,n(1,:),n(2,:),n(3,:));
else
    n = n(:,vn);
    V(vn) = interpn(O,n(1,:),n(2,:),n(3,:),'nearest'); %TODO: linear should be better
end

return