samer@4: % mt_get_transmat_at - Get transition matrix nearest given point in information space.
samer@0: %
samer@0: % mt_get_transmat_at ::
samer@0: %    mt_system ~'Melody Triangle system structure',
samer@0: %    natural   ~'voice Id (1 or greater)',
samer@0: %    K:natural ~'size of transition matrix',
samer@0: %    real      ~'X-coordinate',
samer@0: %    real      ~'Y-coordinate'
samer@0: % -> [[K,K]]   ~'transition matrix',
samer@0: %    [[1,3]]   ~'information coordinates'.
samer@0: %
samer@0: % The selected transition matrix will be shown using mt_show_transmat,
samer@0: 
samer@3: function [T,P,I]=mt_get_transmat_at(Sys,Id,K,X,Y)
samer@3: 	logK=log(K);
samer@0: 	normpos = Sys.map([X;Y])';
samer@3: 	target = normpos*logK;
samer@0: 	tmats = Sys.transmats{K};
samer@0: 	info = Sys.info{K};
samer@0: 	L = size(info,1);
samer@0: 
samer@0: 	% distance from target
samer@0: 	d2 = sum((info(:,1:2) - repmat(target,L,1)).^2,2);
samer@5: 	M = find(d2==min(d2));
samer@15: 	J = M(randnat(length(M)));
samer@0: 	T = tmats(:,:,J);
samer@0: 	I = info(J,:);
samer@9: 	if Sys.shuffle
samer@9: 		perm=randperm(K);
samer@9: 		T=T(perm,perm);
samer@9: 	end
samer@3: 	mt_show_transmat(Id,T,I);
samer@3: 	if nargin>1, P=Sys.revmap(I(1:2)'/logK); end
samer@0: end