Signal Processing Toolbox™

phasedelay - Phase delay of digital filter

Syntax

[phi,w] = phasedelay(b,a,n) [phi,w] = phasedelay(b,a,n,'whole') phi = phasedelay(b,a,w) [phi,f] = phasedelay(b,a,n,fs) [phi,f] = phasedelay(b,a,n,'whole',fs) phi = phasedelay(b,a,f,fs) [phi,w,s] = phasedelay(...) [phi,f,s] = phasedelay(...) phasedelay(b,a,...)

Description

[phi,w] = phasedelay(b,a,n) returns the n-point phase delay response vector phi and the n-point frequency reponse vector w (in radians/sample) of the filter defined by numerator coefficients b and denominator coefficients a. The phase delay response is evaluated at n equally spaced points around the upper half of the unit circle. If n is omitted, it defaults to 512.

[phi,w] = phasedelay(b,a,n,'whole') uses n equally spaced points around the whole unit circle.

phi = phasedelay(b,a,w) returns the phase delay response at frequencies specified in vector w (in radians/sample). The frequencies are normally between 0 and π.

[phi,f] = phasedelay(b,a,n,fs) and [phi,f] = phasedelay(b,a,n,'whole',fs) return the phase delay vector f (in Hz), using the sampling frequency fs (in Hz).

phi = phasedelay(b,a,f,fs) returns the phase delay response at the frequencies specified in vector f (in Hz), using the sampling frequency fs (in Hz)..

[phi,w,s] = phasedelay(...) and [phi,f,s] = phasedelay(...) return plotting information, where s is a structure with fields you can change to display different frequency response plots.

phasedelay(b,a,...) with no output arguments, plots the phase delay response of the filter.

Examples

Example 1

Plot the phase delay response of a constrained least squares FIR filter:

b=fircls1(54,.3,.02,.008); 
phasedelay(b)

Example 2

Plot the phase delay response of an elliptic filter:

[b,a] = ellip(10,.5,20,.4); 
phasedelay(b,a,512,'whole')