[Date Index] [Thread Index] [Author Index]

Forcing Certain Algebraic Forms With FullSimplify

• To: mathgroup at smc.vnet.net
• Subject: [mg123150] Forcing Certain Algebraic Forms With FullSimplify
• From: Scott Fortmann-Roe <scottfr at gmail.com>
• Date: Thu, 24 Nov 2011 06:59:49 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.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