# freqzd

Version:

Computes the complex frequency response vector and the frequency vector of a filter. If you do not request an output, this function plots the magnitude and unwrapped phase of the filter in the current plot window. freqzd(b) is equivalent to freqzd(b, [1], 512). freqzd(b, a) is equivalent to freqzd(b, a, 512).

## Syntax

freqzd(b)
freqzd(b, a)
freqzd(b, a, w)
freqzd(b, a, w, fs)
freqzd(b, a, n)
freqzd(b, a, n, 'whole')
freqzd(b, a, n, fs)
freqzd(b, a, n, 'whole', fs)
h = freqzd(b)
h = freqzd(b, a)
h = freqzd(b, a, n)
h = freqzd(b, a, n, 'whole')
h = freqzd(b, a, n, fs)
h = freqzd(b, a, n, 'whole', fs)
h = freqzd(b, a, w)
h = freqzd(b, a, w, fs)
[h, f] = freqzd(b)
[h, f] = freqzd(b, a)
[h, f] = freqzd(b, a, n)
[h, f] = freqzd(b, a, n, 'whole')
[h, f] = freqzd(b, a, n, fs)
[h, f] = freqzd(b, a, n, 'whole', fs)
Legacy name: freqz

## b

Numerator coefficients of the filter. b is a real vector.

## a

Denominator coefficients of the filter. a is a real vector.

Default: [1]

## w

Frequency points at which you want to evaluate the frequency response. If you do not specify w, MathScript evaluates the frequency response at n points equally spaced around the upper half of the unit circle. w is a vector.

## fs

Sampling frequency in Hz. fs is a scalar.

## n

Number of frequency points. n is a positive integer.

Default: 512

## 'whole'

Directs MathScript to evaluate the frequency response at n points equally spaced around the unit circle.

## h

Frequency response vector of the filter. h is a complex vector.

## f

Discrete frequency vector in radians/sample that corresponds to h. f is a vector.

b = [1, 2];
a = [-1, 1, 1, 3];
n = 32;
[H, F] = freqzd(b, a, n)

Where This Node Can Run:

Desktop OS: Windows

FPGA: This product does not support FPGA devices