Re: Expansion Coefficients in Multivariable Series Expansions?
- To: mathgroup at smc.vnet.net
- Subject: [mg26595] Re: Expansion Coefficients in Multivariable Series Expansions?
- From: "Ersek, Ted R" <ErsekTR at navair.navy.mil>
- Date: Thu, 11 Jan 2001 10:39:09 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
A. E. Siegaman basically had a polynomial in several variables say (x,y,z)
and
as I understand it wanted the coefficient of (x) as returned by the
following.
In[1]:=
poly = 3x + Pi x - 2x y^2 + x z^3;
Part[CoefficientList[poly,{x,y,z}],2,1,1]
Out[1]=
3 + Pi
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Then if poly is a polynomial in (w,u,v,x,y,z) you can get the coefficient of
x by using the following.
Part[ CoefficientList[poly, {w,u,v,x,y,z}], 1,1,1,,2,1,1]
---------------
Lookup CoefficientList on my website
http://www.verbeia.com/mathematica/tips/Tricks.html
for a detailed explanation of this function.
---------------
Regards,
Ted Ersek