Generates the phase responses at specified frequencies for an analog or digital filter described by the numerator and denominator coefficients of its transfer function.

Syntax

Response = PhaseRes(Num, Den, Freq, SampleRate)

Arguments

Name

Description

Num

Vector of the numerator coefficients in descending power of s or z.

Den

Vector of denominator coefficients in descending power of s or z.

Freq

Vector of frequency points (Hz) where the phases are calculated.  For digital filters, the frequency should range from 0 to half the sample rate (Nyquist frequency).

SampleRate

(optional)

A positive scalar specifying the sample rate in Hz. The SampleRate is included for a digital filter. It is omitted for an analog filter.

Output

Name

Description

Response

A vector of phase response (in radians) of the length equal to that of vector Freq.

Example

Find the phase response for a sampling rate of 1000Hz at various frequency points (stored in Freq) by a filter whose numerator and denominator coefficients are given by vectors b and a.

Syntax

Response = PhaseRes(b, a, freq, 1000)

Result

Response is a vector of the phase response at all points in Freq.

See Also:

MagRes