Hello,

I am designing some bandpass filters, starting from a normalized low-pass
Butterworth approximation.

I have the nominator and the denominator of the transfer function.

With:

tf(nom,den);

I get the transfer function. How can I change the variable s to variable
s1=Q*(s/w+w/s)?

On the other hand, how can I change the order of teh values in a vector? For
example if I have vector A=[1 2 3] how can I get B=[ 3 2 1]

thanks a lot,

Paul

# frequency transformation for filter design

Started by ●April 29, 2009

Reply by ●April 30, 20092009-04-30

I do not understand the question but if you want change

V=[a b c d e f] in W = [f e d c b a]

you can use flip left to right

W = fliplr(V)

or if you have V = [a b c d e f] ' (this is a column vector)

flip up down

W = fplipud(V)

On 4/28/09, f...@yahoo.co.uk wrote:

> Hello,

>

> I am designing some bandpass filters, starting from a normalized low-pass

> Butterworth approximation.

> I have the nominator and the denominator of the transfer function.

> With:

> tf(nom,den);

> I get the transfer function. How can I change the variable s to variable

> s1=Q*(s/w+w/s)?

>

> On the other hand, how can I change the order of teh values in a vector? For

> example if I have vector A=[1 2 3] how can I get B=[ 3 2 1]

>

> thanks a lot,

> Paul

>

V=[a b c d e f] in W = [f e d c b a]

you can use flip left to right

W = fliplr(V)

or if you have V = [a b c d e f] ' (this is a column vector)

flip up down

W = fplipud(V)

On 4/28/09, f...@yahoo.co.uk wrote:

> Hello,

>

> I am designing some bandpass filters, starting from a normalized low-pass

> Butterworth approximation.

> I have the nominator and the denominator of the transfer function.

> With:

> tf(nom,den);

> I get the transfer function. How can I change the variable s to variable

> s1=Q*(s/w+w/s)?

>

> On the other hand, how can I change the order of teh values in a vector? For

> example if I have vector A=[1 2 3] how can I get B=[ 3 2 1]

>

> thanks a lot,

> Paul

>