phasemag - phase and magnitude computation

Calling Sequence

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

Parameters

• 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))

Examples

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')');
 

See Also

repfreq  gainplot  atan  bode