Scilab Function

phasemag - phase and magnitude computation

### Sequence d'appel

  `[phi,db]=phasemag(z [,mod])`

### Parametres

- `z` : matrix or row vector of complex numbers.
- `mod` : character string

- `mod='c'` : "continuous" representation between -infinity and +360 degrees (default)
- `mod='m'` : representation between -360 and 0 degrees

- `phi` : phases (in degree) of `z`.
- `db` : magnitude (in Db)

### Description

`phasemag` computes the phases and magnitudes of the entries of a complex matrix. For `mod='c'` `phasemag` computes `phi(:,i+1)` to minimize the distance with `phi(:,i)`, i.e. it tries to obtain a "continuous representation" of the phase.

To obtain the phase between -%pi and %pi use `phi=atan(imag(z),real(z))`

### Exemples

    s=poly(0,'s');
    h=syslin('c',1/((s+5)*(s+10)*(100+6*s+s*s)*(s+.3)));
    [frq,rf]=repfreq(h,0.1,20,0.005);
    xbasc(0);
    plot2d(frq',phasemag(rf,'c')');
    xbasc(1);
    plot2d(frq',phasemag(rf,'m')');

### Voir aussi

`repfreq` `gainplot` `atan` `bode`