gusucode.com > 用matlab仿真0到9十个数字的语音识别源码程序 > Speech-Recogenition/sqdist.m
function m = sqdist(p, q, A) % SQDIST Squared Euclidean or Mahalanobis distance. % SQDIST(p,q) returns m(i,j) = (p(:,i) - q(:,j))'*(p(:,i) - q(:,j)). % SQDIST(p,q,A) returns m(i,j) = (p(:,i) - q(:,j))'*A*(p(:,i) - q(:,j)). % From Tom Minka's lightspeed toolbox [d, pn] = size(p); [d, qn] = size(q); if nargin == 2 pmag = sum(p .* p, 1); qmag = sum(q .* q, 1); m = repmat(qmag, pn, 1) + repmat(pmag', 1, qn) - 2*p'*q; %m = ones(pn,1)*qmag + pmag'*ones(1,qn) - 2*p'*q; else if isempty(A) | isempty(p) error('sqdist: empty matrices'); end Ap = A*p; Aq = A*q; pmag = sum(p .* Ap, 1); qmag = sum(q .* Aq, 1); m = repmat(qmag, pn, 1) + repmat(pmag', 1, qn) - 2*p'*Aq; end