annotate toolboxes/distance_learning/mlr/distance/setDistanceDODMKL.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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wolffd@0 1 function D = setDistanceDODMKL(X, W, Ifrom, Ito)
wolffd@0 2 %
wolffd@0 3 % D = setDistanceDODMKL(X, W, Ifrom, Ito)
wolffd@0 4 %
wolffd@0 5 % X = d-by-n data matrix
wolffd@0 6 % W = m-by-m-by-n PSD matrix
wolffd@0 7 % Ifrom = k-by-1 vector of source points
wolffd@0 8 % Ito = j-by-1 vector of destination points
wolffd@0 9 %
wolffd@0 10 % D = n-by-n matrix of squared euclidean distances from Ifrom to Ito
wolffd@0 11 % D is sparse, and only the rows corresponding to Ifrom and
wolffd@0 12 % columns corresponding to Ito are populated.
wolffd@0 13
wolffd@0 14 [d,n,m] = size(X);
wolffd@0 15 L = W.^0.5;
wolffd@0 16
wolffd@0 17 D = 0;
wolffd@0 18 for i = 1:m
wolffd@0 19 for j = i:m
wolffd@0 20 Vfrom = bsxfun(@times, squeeze(L(i,j)), X(:,Ifrom,i) + X(:,Ifrom,j));
wolffd@0 21
wolffd@0 22 if nargin == 4
wolffd@0 23 Vto = bsxfun(@times, squeeze(L(i,j)), X(:,Ito,i) + X(:,Ito,j));
wolffd@0 24 else
wolffd@0 25 Vto = bsxfun(@times, squeeze(L(i,j)), X(:,:,i) + X(:,:,j));
wolffd@0 26 Ito = 1:n;
wolffd@0 27 end
wolffd@0 28
wolffd@0 29 if i == j
wolffd@0 30 s = 0.5;
wolffd@0 31 else
wolffd@0 32 s = 1;
wolffd@0 33 end
wolffd@0 34
wolffd@0 35 D = D + s * distToFrom(n, Vto, Vfrom, Ito, Ifrom);
wolffd@0 36 end
wolffd@0 37 end
wolffd@0 38
wolffd@0 39 end