phaseplot

frequency phase plot

Calling Sequence

phaseplot(sl)
phaseplot(sl,fmin,fmax [,step] [,comments] )
phaseplot(frq,db,phi [,comments])
phaseplot(frq, repf [,comments])

Arguments

:sl a single input multiple output (SIMO) linear dynamical system (see

`syslin`_).

: :fmin real scalar: the minimum frequency (in Hz) to be represented. : :fmax real scalar: the maximum frequency (in Hz) to be represented. : :step real scalar: the frequency discretization step (logarithmic

scale)). If it is not specified the alorithm uses adaptative frequency steps.

: :comments a character string vector: the legend label to be

associated with each curve. Optional value is the empty array.

: :frq a row vector or an n x m array: The frequency discretization in

Hz.

: :db an n x m array: the magnitudes corresponding to frq. This

argument is not used, it only appears to make phaseplot have the same calling sequence as gainplot and bode.

: :phi an n x m array: the phases in degree corresponding to frq.

The phaseplot function plots the curves frq(i,:) versus phi(i,:)

: :repf an n x m complex array. The phaseplot function plots the

curves frq(i,:) versus phase(repf(i,:))

:

Description

This function draws the phase of the frequency response of a system. The system can be given under different representations:

• phaseplot(sl,...) case 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. In this case the frequencies can be given by:

  • the lower and upper bounds in Hz fmin, fmax and an optional frequency step step. The default values for fmin and fmax`are `1.e-3, 1.e3 if sl is continuous-time or 1.e-3, 0.5/sl.dt (nyquist frequency) if sl is discrete-time. If the step argument is omitted the function use an adaptative frequency step (see `calfrq`_).
  • a row vector or a 2D array frq which gives the frequency values in Hz. 2D array can be used for multi-output systems if one wants to have different frequency discretization for each input/output couple.

• phaseplot(frq,...) case This case allows to draw frequency phase plots for previously computed frequency responses. The frequency response can be given either by it’s complex representation repf or by it’s magnitude phase representation db, phi . frq and repf must be row vectors or n x m arrays (each row represent an input/output couple) .

The