# Plot zero-pole from frequency response matrix

I've represented with Matlab a system with three degrees of freedom. I'm trying to plot a pole-zero map from my Frequency Response Matrix H(w) in the case of Damped-Forced :

w=0:0.01:30;
for ii=1:length(w)
FRF=inv(-w(ii)^2*M_gen+1i*w(ii)*C_gen_approx+K_gen);
FRF11(ii)=FRF(1,1); FRF12(ii)=FRF(1,2); FRF13(ii)=FRF(1,3);
FRF21(ii)=FRF(2,1); FRF22(ii)=FRF(2,2); FRF23(ii)=FRF(2,3);
FRF31(ii)=FRF(3,1); FRF32(ii)=FRF(3,2); FRF33(ii)=FRF(3,3);
end


Does anybody know if it is possible do this directly with some possible solution or do I have to get values of my FRF end, then generate pole-zero maps?