Scilab Home page | Wiki | Bug tracker | Forge | Mailing list archives | ATOMS | File exchange
Please login or create an account
Change language to: English - Português - 日本語 - Русский

Please note that the recommended version of Scilab is 6.0.1. This page might be outdated.
See the recommended documentation of this function

Aide de Scilab >> Traitement du Signal > filters > group


group delay for digital filter

Calling Sequence

[tg [,fr]] = group(npts, H) (call with a siso transfert function)
[tg [,fr]] = group(npts, C) (call with a vector of transfert functions, cascaded second order representation)

[tg [,fr]] = group(npts, F) (call with the vector of an FIR filter coefficients)
[tg [,fr]] = group(npts, a1i, a2i, b1i, b2i) (call with 4 vectors of numbers, cascaded second order Deczky representation)



integer : number of points desired in calculation of group delay


in coefficient, polynomial, rational polynomial, or cascade polynomial form this variable is the transfer function of the filter. In coefficient polynomial form this is a vector of coefficients (see below).


in coeff poly form this is a vector of coeffs


in coeff poly form this is a vector of coeffs


in coeff poly form this is a vector of coeffs


values of group delay evaluated on the grid fr


grid of normalized frequency values where group delay is evaluated


Calculate the group delay of a digital filter with transfer function h(z).

The filter specification can be in coefficient form, polynomial form, rational polynomial form, cascade polynomial form, or in coefficient polynomial form.

In the coefficient polynomial form the transfer function is formulated by the following expression



s = poly(0, "s");
h_cont = syslin("c", 1/(s-10));
h = ss2tf(cls2dls(tf2ss(h_cont), 0.1));
[tg, fr] = group(100, h);
plot(fr, tg)
Scilab Enterprises
Copyright (c) 2011-2017 (Scilab Enterprises)
Copyright (c) 1989-2012 (INRIA)
Copyright (c) 1989-2007 (ENPC)
with contributors
Last updated:
Thu Oct 02 13:54:32 CEST 2014