bode(1)

NAME
bode - Bode plot

CALLING SEQUENCE
bode(sl,[fmin,fmax] [,step] [,comments] )
bode(sl,frq [,comments] )
bode(frq,db,phi [,comments])
bode(frq, repf  [,comments])

PARAMETERS

sl  : syslin list (SISO or SIMO linear system) in continuous or discrete time.

fmin,fmax
    : real (frequency bounds (in Hz))

step
    : real (logarithmic step.)

comments
    : vector of character strings (captions).

frq : row vector or matrix (frequencies (in Hz) ) (one row for each SISO subsystem).

db  : row vector or matrix ( magnitudes (in Db)). (one row for each SISO subsystem).

phi : row vector or matrix ( phases (in degree)) (one row for each SISO subsystem).

repf
    : row vector or matrix of complex numbers (complex frequency response).

DESCRIPTION
Bode plot, i.e magnitude and phase of the frequency response of sl. sl can be a continuous-time or discrete-time SIMO system (see syslin). In case of multi-output the outputs are plotted with different symbols.

The frequencies are given by the bounds fmin,fmax (in Hz) or by a row-vector (or a matrix for multi-output) frq.

step is the ( logarithmic ) discretization step. (see calfrq for the choice of default value).

comments is a vector of character strings (captions).

db,phi are the matrices of modulus (in Db) and phases (in degrees). (One row for each response).

repf matrix of complex numbers. One row for each response.

Default values for fmin and fmax are 1.d-3, 1.d+3 if sl is continuous-time or 1.d-3, 0.5 if sl is discrete-time. Automatic discretization of frequencies is made by calfrq.

EXAMPLE
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))
title='(s^2+2*0.9*10*s+100)/(s^2+2*0.3*10.1*s+102.01)';
bode(h,0.01,100,title);
h1=h*syslin('c',(s^2+2*0.1*15.1*s+228.01)/(s^2+2*0.9*15*s+225))
bode([h1;h],0.01,100,['h1';'h'])

SEE ALSO
black, nyquist, freq, repfreq, g_margin, p_margin, calfrq, phasemag