group(1)

NAME
group - group delay for digital filter

CALLING SEQUENCE
[tg,fr]=group(npts,a1i,a2i,b1i,b2i)

PARAMETERS

npts
    : integer : number of points desired in calculation of group delay

a1i : 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).

a2i : in coeff poly form this is a vector of coeffs

b1i : in coeff poly form this is a vector of coeffs

b2i : in coeff poly form this is a vector of coeffs

tg  : values of group delay evaluated on the grid fr

fr  : grid of frequency values where group delay is evaluated

DESCRIPTION
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 tranfer function is formulated by the following expression

 h(z)=prod(a1i+a2i*z+z**2)/prod(b1i+b2i*z+z**2)

AUTHOR
C. B.