Download Help (Windows Only) |
Owning Class: filter design
Requires: MathScript RT Module
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, 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
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).
Name | Description |
---|---|
b | Specifies the numerator coefficients of the filter. b is a real or complex vector. |
a | Specifies the denominator coefficients of the filter. a is a real or complex vector. The default is [1]. |
w | Specifies the frequency points at which you want to evaluate the frequency response. If you do not specify w, LabVIEW evaluates the frequency response at n points equally spaced around the upper half of the unit circle. w is a vector. |
fs | Specifies the sampling frequency in Hz. fs is a scalar. |
n | Specifies the number of frequency points. n is a positive integer. The default is 512. |
'whole' | Directs LabVIEW to evaluate the frequency response at n points equally spaced around the unit circle. |
Name | Description |
---|---|
h | Returns the frequency response vector of the filter. h is a complex vector. |
f | Returns the discrete frequency vector in radians/sample that corresponds to h. f is a vector. |
The following table lists the support characteristics of this function.
Supported in the LabVIEW Run-Time Engine | Yes (if you request output) |
Supported on RT targets | Yes (if you request output) |
Suitable for bounded execution times on RT | Not characterized |
b = [1, 2];
a = [-1, 1, 1, 3];
n = 32;
[H, F] = freqzd(b, a, n)
b = [3, 4];
a = [1, -3, 2, 5];
n = 10;
fs = 12;
[H, F] = freqzd(b, a, n, 'whole', fs)