function [Mt, Ms] = transmission(R, a1, n1, n2) % [Mt, Ms] = transmission(R, a1, n1, n2) if length(R) > 1 Rt = R(1); Rs = R(2); else Rt = R; Rs = R; end % degrees to radians a1 = a1 * pi / 180; % output angle from refraction (snell's law) a2 = asin(n1*sin(a1)/n2); % define angle/index change dn = (n2*cos(a2) - n1*cos(a1)) / (cos(a1)*cos(a2)); % effective RoC Ret = Rt/dn; Res = Rs/dn; % tangential Mt = [cos(a2)/cos(a1) 0; 1/Ret cos(a1)/cos(a2)]; % sagittal Ms = [1 0; 1/Res 1];