gusucode.com > qit_matlab_0.10.0工具箱源码程序 > qit/utils/lmul.m
function S = lmul(L, q) % LMUL Superoperator equivalent for multiplying from the left. % S = lmul(L); % % L*rho == inv_vec(lmul(L)*vec(rho)) % Ville Bergholm 2009 if (nargin < 2) q = size(L, 2); % assume target is a square matrix end S = kron(speye(q), L);