//Caption:transfer_function_using_mason's_gain_formula // example 4.4.7 //page 70 syms G1 G2 G3 H1; // forward path denoted by P1,P2 and so on and loop by L1,L2 and so on //path factor by D1,D2 and so on and graph determinant by D P1=G1*G3*G4; P2=G1*(-G2); L1=G3*G4*(-1); L2=G1*G3*H1*(-1); L3=G1*G3*H1*(-1); L4=G1*(-G2)*(-1)*G3*H1*(-1); L5=G1*(-G2)*(-1)*G3*H1*(-1); L4=simple(L4); L5=simple(L5); D1=1; D2=1; D=1-(L1+L2+L3+L4+L5); D=simple(D) Y=(P1*D1+P2*D2)/D; Y=simple(Y); disp(Y,"C(s)/R(s)=")