residue with symbolic toolbox

hello,

i wish to calculate the partial fraction expansion of:

1/((z-a)(z+3)(z-5))

it doesn't seem like i can do it using the residue() matlab command,
is there any way i can do this in matlab?

many regards,
juan Start a New Thread

Hello:

Juan:

If your partial fractions expression is denoted by H, then try to use the trick diff(int(H)). Usually, MATLAB will return the original expression expanded into partial fractions. I hope this helps.

Best Regards

Peter Start a New Thread

hi,
thanks for all the responses,
this seems the simplest, i also tried the int(diff(H)) trick and that
does indeed work too,
thanks again

On 05/08/2010, at 7:46 PM, Vaibhav Singh wrote:

> Hi Juan,
>
> If u have a equation like 1/(x-a)(x-b)(x-c), then the partial
> fraction is in form of A/(x-a)+B/(x-b)+C/(x-c), with the values of
> A B C being,
>
> A = (a-c)(a-b)
> B = (b-a)(b-c)
> C = (c-a)(c-b)
>
> So, no need of any explicit matlab command for this.
>
> Regards - Vaibhav
>
> On Thu, Jul 29, 2010 at 2:32 PM, Juan Vesa
> wrote:
>
> hello,
>
> i wish to calculate the partial fraction expansion of:
>
> 1/((z-a)(z+3)(z-5))
>
> it doesn't seem like i can do it using the residue() matlab command,
> is there any way i can do this in matlab?
>
> many regards,
> juan
>
> --
> Vaibhav Singh
> BE(Hons.) Electronics And Instrumentation
> BITS-Pilani Start a New Thread