Re: Re: Coefficient in multivariate series
- To: mathgroup at smc.vnet.net
- Subject: [mg3624] Re: [mg3576] Re: Coefficient in multivariate series
- From: Roberto Colistete Junior <roberto at verao.cce.ufes.br>
- Date: Sat, 30 Mar 1996 02:46:01 -0500
- Sender: owner-wri-mathgroup at wolfram.com
A simpler form is to use Coefficient[expr, form], where form can be
any product of powers, as explained in the help or manual. For example :
In[1]:= Coefficient[Expand[(1+x+y)^2*(2+y)*(5+z)^4], x*y*z^3]
Out[1]:= 120
Roberto Colistete Junior
<roberto at cce.ufes.br>
Departamento de Fisica
Universidade Federal do Espirito Santo
Brasil
Harald Berndt wrote:
>
> Samuel Bengmark wrote:
> >
> > I wonder if anyone out there knows how to get mathematica
> > to extract a coefficient of a monomial in a multivariate to
> > series or polynomial. For example how do I get mathematica to
> > give me the coefficient of x*y*z^3 in (1+x+y)^2*(2+y)*(5+z)^4.
>
>
> It's not very elegant, but I could'n get any simpler forms to work ...
> This will do it for you:
>
> First[
> Select[t,
> (MemberQ[#, x] && MemberQ[#, y] && MemberQ[#, Power[z, 3]])& ]
> ]
>
> Best,
>
> --
> ______________________________________________________________________
> Harald Berndt, University of California
> Research Specialist Forest Products Laboratory
>
> Phone: 510-215-4224 FAX: 510-215-4299
>
>
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