Re: Forcing Certain Algebraic Forms With FullSimplify

*To*: mathgroup at smc.vnet.net*Subject*: [mg123161] Re: Forcing Certain Algebraic Forms With FullSimplify*From*: "David Park" <djmpark at comcast.net>*Date*: Fri, 25 Nov 2011 04:54:19 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <1845150.123858.1322134597179.JavaMail.root@m06>

This is easy with the Presentations application: << Presentations` a*b + g // FactorOut[a] a (b + g/a) David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Scott Fortmann-Roe [mailto:scottfr at gmail.com] Hi, I would like to have Mathematica generate an output for an equation where a certain variable is isolated. For instance, I have the equation "a*b+g". I would like "b" to not be multiplied by anything in the result. Thus, I would prefer the form "a(b+g/a)". I have attempted to do this with FullSimplify and ComplexityFunction. The complexity function (cf) evaluates the way I want it to, but for some reason FullSimplify gives me the answer I don't want. Sample code: cf[e_] := 100 Count[e, Times[b, __], Infinity] + LeafCount[e] ; cf[a b + g] cf[a (b + g/a)] FullSimplify[a b + g, ComplexityFunction -> cf] Output: 105 9 a b + g Any ideas? Thank you, Scott