## Name

trans — low-pass to other filter transform

## Calling Sequence

hzt=trans(hz,tr_type,frq)
hzt=trans(pd,zd,gd,tr_type,frq)

## Parameters

- hz
a single input single output discrete transfer function, the low pass filter

- pd
Vector of given filter poles

- zd
Vector of given filter zeros

- gd
scalar: the given filter gain

- tr_type
string, the type of transformation, see description for possible values

- frq
2-vector of discrete cut-off frequencies
(i.e.,`0<frq<.5`

). see description
for details.

- hzt
transformed filter transfert function.

## Description

function for transforming standardized low-pass filter given its
poles-zeros_gain representation into
one of the following filters:

- tr_type='lp'
low pass filter, the cutoff frequency is given by the
first entry of `frq`

, the second one is ignored.

- tr_type='hp'
high pass filter, the cutoff frequency is given by the
first entry of `frq`

, the second one is ignored.

- tr_type='bp'
band pass filter, the frequency range is given by `frq(1)`

and `frq(2)`

.

- tr_type='sb'
stop band filter, the frequency range is given by `frq(1)`

and `frq(2)`

.

## Examples

clf()
Hlp=iir(3,'lp','ellip',[0.1 0],[.08 .03]);
Hbp=trans(Hlp,'bp',[0.01 0.1]);
Hsb=trans(Hlp,'sb',[0.01 0.1])
clf();gainplot([Hlp;Hbp;Hsb],1d-3,0.48);
l=legend(['original low pass';'band pass';'stop band']);
l.legend_location="in_lower_left";