# calfrq

frequency response discretization

## Calling Sequence

    [frq,bnds,split]=calfrq(h,fmin,fmax)

## Arguments

h

  Linear system in state space or transfer representation ( `see syslin` )

fmin,fmax

  real scalars (min and max frequencies in Hz)

frq

  row vector (discretization of the frequency interval)

bnds

  vector `[Rmin Rmax Imin Imax]` where `Rmin` and `Rmax` are the lower and upper bounds of the frequency response real part, `Imin` and `Imax` are the lower and upper bounds of the frequency response imaginary part,

split

  vector of frq splitting points indexes

## Description

frequency response discretization; `frq` is the discretization of `[fmin,fmax]` such that the peaks in the frequency response are well represented.

Singularities are located between `frq(split(k)-1)` and `frq(split(k))` for `k>1`.

## Examples

    s=poly(0,'s')
    h=syslin('c',(s^2+2*0.9*10*s+100)/(s^2+2*0.3*10.1*s+102.01))
    h1=h*syslin('c',(s^2+2*0.1*15.1*s+228.01)/(s^2+2*0.9*15*s+225))
    [f1,bnds,spl]=calfrq(h1,0.01,1000);
    rf=repfreq(h1,f1);
    plot2d(real(rf)',imag(rf)')

## See Also

- bode
- black
- nyquist
- freq
- repfreq
- logspace