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transfer function plot problem

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fima v
fima v on 4 Sep 2019
Commented: fima v on 4 Sep 2019
Hello, I have extracted the poles and zeros of a circuit which have the following response shown in a plot bellow.
the POLES and ZEROS of the circuit are attached.
however when i tried to put them into a transfer function expression as shown in the code bellow it gives me
sys = NaN and an empty plot
Where did i go wrong ?
Thanks.
z=[-1.28811872803795e-09+3.75032438366853e-10i;
-1.28811872803795e-09-3.75032438366853e-10i;
-1.27120508227557e-09+1.46546199782833e-09i;
-1.27120508227557e-09-1.46546199782833e-09i;
-3.32881226000323e-09+9.39321860988066e-11i;
-3.32881226000323e-09-9.39321860988066e-11i;
-1.58271684302383e-09+3.99452158295292e-09i;
-1.58271684302383e-09-3.99452158295292e-09i;
-5.82131957722562e-06+0.00000000000000e+00i;
5.86257744501881e-06+0.00000000000000e+00i;
-3.97879334830376e+02+1.16773714820167e+04i;
-3.97879334830376e+02-1.16773714820167e+04i;
-1.26876548375538e+04+5.92462339644297e+04i;
-1.26876548375538e+04-5.92462339644297e+04i;
-1.22897755043826e+04+1.50129180496307e+05i;
-1.22897755043826e+04-1.50129180496307e+05i;
-2.37898350744872e+10+0.00000000000000e+00i;
2.38692896865366e+10+0.00000000000000e+00i;
-1.83626068795164e+11+1.57681364106391e+11i;
-1.83626068795164e+11-1.57681364106391e+11i;
1.83757221349466e+11+1.57733433284606e+11i;
1.83757221349466e+11-1.57733433284606e+11i;
-3.52043680810489e+11+0.00000000000000e+00i;
3.52133420753001e+11+0.00000000000000e+00i;
-3.43282629853052e+11+3.92816887251620e+11i;
-3.43282629853052e+11-3.92816887251620e+11i;
3.43331696868923e+11+3.92794659000565e+11i;
3.43331696868923e+11-3.92794659000565e+11i;
-6.38933586270784e+11+0.00000000000000e+00i;
6.39013681124312e+11+0.00000000000000e+00i;
-7.41366644869900e+11+0.00000000000000e+00i;
7.41459685162969e+11+0.00000000000000e+00i;
-7.16813058132076e+11+3.17835645085742e+11i;
-7.16813058132076e+11-3.17835645085742e+11i;
7.16937051677754e+11+3.17779565482882e+11i;
7.16937051677754e+11-3.17779565482882e+11]
p=[-1.17526574606346e-08+0.00000000000000e+00i;
-1.45539022282902e-08+0.00000000000000e+00i;
-2.05380336431976e-08+0.00000000000000e+00i;
-2.55828321866515e-08+0.00000000000000e+00i;
-4.56660033199091e-08+0.00000000000000e+00i;
-5.70884825512686e-08+0.00000000000000e+00i;
-1.81058930649108e-07+0.00000000000000e+00i;
-2.26809326278153e-07+0.00000000000000e+00i;
-2.07048762127127e+01+5.79122928914659e+03i;
-2.07048762127127e+01-5.79122928914659e+03i;
-3.83164553845592e+02+1.16216446323155e+04i;
-3.83164553845592e+02-1.16216446323155e+04i;
-1.26711513946503e+04+6.55349709090204e+04i;
-1.26711513946503e+04-6.55349709090204e+04i;
-1.37893284168987e+04+1.38236035864718e+05i;
-1.37893284168987e+04-1.38236035864718e+05i;
-1.21701532452899e+06+0.00000000000000e+00i;
-3.27874730871924e+07+0.00000000000000e+00i;
-2.56974745105871e+10+0.00000000000000e+00i;
2.57902230577189e+10+0.00000000000000e+00i;
-2.00885121575103e+11+0.00000000000000e+00i;
2.00994270339200e+11+0.00000000000000e+00i;
-2.09729105616755e+11+0.00000000000000e+00i;
2.09829607497857e+11+0.00000000000000e+00i;
-3.67183927043333e+11+0.00000000000000e+00i;
3.67280123011875e+11+0.00000000000000e+00i;
-3.93421324148177e+11+0.00000000000000e+00i;
3.93513018627735e+11+0.00000000000000e+00i;
-5.85494774575287e+11+4.93981433401239e+09i;
-5.85494774575287e+11-4.93981433401239e+09i;
5.85599337665681e+11+4.93428043170709e+09i;
5.85599337665681e+11-4.93428043170709e+09i;
-6.86534178758184e+11+0.00000000000000e+00i;
6.86625532723185e+11+0.00000000000000e+00i;
-7.28937758682295e+11+0.00000000000000e+00i;
7.29035537891136e+11+0.00000000000000e+00i;
-8.27479933780269e+11+0.00000000000000e+00i;
8.27565870925879e+11+0.00000000000000e+00i;
-9.10585117712558e+11+1.10238827198810e+11i;
-9.10585117712558e+11-1.10238827198810e+11i;
9.10657754476142e+11+1.10250967050881e+11i;
9.10657754476142e+11-1.10250967050881e+11i;
-9.47150572658139e+11+0.00000000000000e+00i;
9.47241034341615e+11+0.00000000000000e+00i;
-9.80609936035125e+11+0.00000000000000e+00i;
9.80695673294753e+11+0.00000000000000e+00i]
k=1;
[num,den]=zp2tf(z,p,k)
sys=tf(num,den)
bode(sys)

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Answers (1)

Raj
Raj on 4 Sep 2019
I don't think you need to use 'zp2tf' and then 'tf' to get your transfer function. You can directly use:
sys=zpk(z,p,k)
bode(sys)

  1 Comment

fima v
fima v on 4 Sep 2019
i tried it ,its not the original function plotted.

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