Re: Simplifying the *Individual Coefficients* in Series Expansions?
- To: mathgroup at smc.vnet.net
- Subject: [mg35235] Re: [mg35214] Simplifying the *Individual Coefficients* in Series Expansions?
- From: Andrzej Kozlowski <andrzej at tuins.ac.jp>
- Date: Wed, 3 Jul 2002 05:14:22 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
What do you mean by: "will not evaluate numerically"??? I was going to suggest simply: Collect[Simplify[fS],x] but this ought to produce something similar to your last approach, and since I can't see anything wrong with that I can't tell if the same problem will not occur with my proposed solution. Andrzej Kozlowski Toyama International University JAPAN http://platon.c.u-tokyo.ac.jp/andrzej/ On Tuesday, July 2, 2002, at 03:12 PM, AES wrote: > I have a long expression f that involves integers times various > powers of symbols b and x, i.e. > > f = ratio of two lengthy polynomials in b and x > > If I series expand this in x , viz. > > fS = Series[f, {x, 0, 2}] // Normal > > I get an answer in the form > > fS = c1 x + c2 x^2 > > where the coefficients c1 and c2 in the resulting series expansion > come out as rather messy expressions (ratios of polynomials). In my > problem, however, these coefficients actually happen to simplify > substantially (since there are common factors in their numerators and > denominators), and I'd like to have them in simplified form. But if I > write > > fS // Simplify > > I'm back in lengthy polynomial form; and if I try something like > > fS = (Coefficient[fS, x] // Simplify) x + > (Coefficient[fS, x^2] // Simplify) x^2 > > I get an expression that looks great, but will not evaluate numerically. > > Any easy way around this? > > >