Signal Processing Toolbox
phasedelay

CPhase delay of digital filters

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 .

```[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')

```

`freqz`, `fvtool`, `phasez`, `grpdelay`