grpdelay (MathScript RT Module Function)

LabVIEW 2012 MathScript RT模块帮助

»查看产品信息 下载帮助（仅限Windows）

Owning Class: filter design

Requires: MathScript RT Module

Syntax

grpdelay(b)

grpdelay(b, a)

grpdelay(b, a, n)

grpdelay(b, a, n, 'whole')

grpdelay(b, a, n, f)

grpdelay(b, a, n, 'whole', f)

grpdelay(b, a, w)

grpdelay(b, a, w, f)

gd = grpdelay(b, a)

gd = grpdelay(b, a, n)

gd = grpdelay(b, a, n, 'whole')

gd = grpdelay(b, a, n, f)

gd = grpdelay(b, a, n, 'whole', f)

gd = grpdelay(b, a, w)

gd = grpdelay(b, a, w, f)

[gd, fr] = grpdelay(b)

[gd, fr] = grpdelay(b, a)

[gd, fr] = grpdelay(b, a, n)

[gd, fr] = grpdelay(b, a, n, 'whole')

[gd, fr] = grpdelay(b, a, n, f)

[gd, fr] = grpdelay(b, a, n, 'whole', f)

[gd, fr] = grpdelay(b, a, w)

[gd, fr] = grpdelay(b, a, w, f)

Description

Computes the group delay of a filter. If you do not request an output, this function plots the group delay in the current plot window. grpdelay(b) is equivalent to grpdelay(b, , 512). grpdelay(b, a) is equivalent to grpdelay(b, a, 512).

Examples

Inputs

Name Description
b Specifies the forward filter coefficients. b is a real vector.
a Specifies the backward filter coefficients. a is a real vector. The default is .
n Specifies the number of frequencies to use. n is a nonnegative integer. The default is 512.
w Specifies predefined frequencies. 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.
f Specifies the sampling frequency. f is a scalar.
'whole' Indicates that you want to use the whole unit circle.

Outputs

Name Description
gd Returns the group delay of the filter defined by a and b. gd is a real vector.
fr Returns the corresponding frequencies of the filter. fr is a real vector.

Details

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

Examples

W = 0:0.01:0.5;
A = ;
B = [1, 4, 1, 6];
GD = grpdelay(B, A, W)

b = [2, 3, 7, 1];
a = [1, 7, 3, 10];
n = 250;
f = 20;
[GD, FR] = grpdelay(b, a, n, 'whole', f)

﻿