Re: Forcing Certain Algebraic Forms With FullSimplify

*To*: mathgroup at smc.vnet.net*Subject*: [mg123193] Re: Forcing Certain Algebraic Forms With FullSimplify*From*: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>*Date*: Sat, 26 Nov 2011 05:06:36 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

Hi, Scott, There is a package "Presentations" of David Park that enables one doing such things. There are several ways doing with the presentations of what you need. For example: Needs["Presentations`Manipulations`"]; a b + g // FactorOut[a] a (b + g/a) Alexei 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 Alexei BOULBITCH, Dr., habil. IEE S.A. ZAE Weiergewan, 11, rue Edmond Reuter, L-5326 Contern, LUXEMBOURG Office phone : +352-2454-2566 Office fax: +352-2454-3566 mobile phone: +49 151 52 40 66 44 e-mail: alexei.boulbitch at iee.lu<mailto:alexei.boulbitch at iee.lu>