wolffd@0: function D = distToFrom(n, Vto, Vfrom, Ito, Ifrom)
wolffd@0:     Cross           = -2 * Vto' * Vfrom;
wolffd@0:     Tonorm          = sum(Vto .^2, 1)';
wolffd@0:     Fromnorm        = sum(Vfrom .^2, 1);
wolffd@0: 
wolffd@0:     D               = zeros(n);
wolffd@0:     D(Ito,Ifrom)    = bsxfun(@plus, bsxfun(@plus, Cross, Tonorm), Fromnorm);
wolffd@0: end