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See the recommended documentation of this function

Ajuda Scilab >> Processamento de Sinais > frfit

frfit

frequency response fit

Calling Sequence

sys=frfit(w,fresp,order)
[num,den]=frfit(w,fresp,order)
sys=frfit(w,fresp,order,weight)
[num,den]=frfit(w,fresp,order,weight)

Arguments

w

positive real vector of frequencies (Hz)

fresp

complex vector of frequency responses (same size as w)

order

integer (required order, degree of den)

weight

positive real vector (default value ones(w)).

num,den

stable polynomials

Description

sys=frfit(w,fresp,order,weight) returns a bi-stable transfer function G(s)=sys=num/den, of of given order such that its frequency response G(w(i)) matches fresp(i), i.e. freq(num,den,%i*w) should be close to fresp. weight(i) is the weight given to w(i).

Examples

w=0.01:0.01:2;
s=poly(0,'s');
G=syslin('c',2*(s.^2+0.1*s+2), (s.^2+s+1)*(s.^2+0.3*s+1));
fresp=repfreq(G,w);
Gid=frfit(w,fresp,4);
frespfit=repfreq(Gid,w);
bode(w,[fresp;frespfit])

See Also

  • frep2tf — transfer function realization from frequency response
  • factors — fatoração numérica real
  • cepstrum — cepstrum calculation
  • mrfit — frequency response fit
  • freq — frequency response
  • calfrq — frequency response discretization
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Last updated:
Tue Apr 02 17:37:05 CEST 2013