[zeros, poles, gain]=zpkdata(GH,'v)i contribution in degrees contrib =(180/pi)*(sum(angle(s1 zeros)) sum(angle(s1- poles))) contrib -270 The root locus angle criterion gives lead contribution ∠G(s1)H(S1)+p=-180 =-180-∠G(5)H(S1)(6.12) 2022-2-11 162022-2-11 16 [zeros,poles,gain]=zpkdata(GH, 'v'); % contribution in degrees contrib = (180/pi)*(sum(angle(s1 - zeros)) - sum(angle(s1 - poles))) contrib = -270 The root locus angle criterion gives lead contribution 180 ( ) ( ) ( ) ( ) 180 1 1 1 1 G s H s G s H s c c           (6.12)