Re: Question about Coefficient
- To: mathgroup@smc.vnet.net
- Subject: [mg11531] Re: Question about Coefficient
- From: Paul Abbott <paul@physics.uwa.edu.au>
- Date: Fri, 13 Mar 1998 12:22:22 -0500
- Organization: University of Western Australia
- References: <6e83ab$nbs@smc.vnet.net>
Bob McDonald wrote:
> I am trying to take a list of polynomials or monomials, say
>
> {x1 x2^2,x1^3,0}
>
> and determine the coefficients of each of the monomials. For example,
> given
>
> {x1^3,0,0}
>
> I want to find that the coefficient of x1^3 is {1,0,0}
>
> This works using, e.g.
>
> Coefficient[{x1^2 x2,0,0},x1^2 x2]
>
> which yields {1,0,0}.
?? I get
In[1]:= Coefficient[{x1^2 x2,0,0},x1^2 x2] Out[1]= {0,0,0}
> Could someone suggest another function or method for doing this?
I think CoefficientList and Variables (or maybe the undocumented
MonomialList) would be more useful, e.g.,
In[2]:= CoefficientList[{x1^2 x2,2x1+x2,3x2},Variables[{x1^2
x2,2x1+x2,3x2}]]
Out[2]= {{{0, 0}, {0, 0}, {0, 1}}, {{0, 1}, {2, 0}}, {{0, 3}}}
Cheers,
Paul
____________________________________________________________________
Paul Abbott Phone: +61-8-9380-2734
Department of Physics Fax: +61-8-9380-1014
The University of Western Australia Nedlands WA 6907
mailto:paul@physics.uwa.edu.au AUSTRALIA
http://www.pd.uwa.edu.au/~paul
God IS a weakly left-handed dice player
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