Re: Inverse of "PowerExpand"
- To: mathgroup at smc.vnet.net
- Subject: [mg51981] Re: Inverse of "PowerExpand"
- From: Karl_boehme_9 at msn.com (Klaus G)
- Date: Sat, 6 Nov 2004 02:07:46 -0500 (EST)
- References: <cm267l$hdg$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
> Unfortunately FunctionExpand does not return quite what what we want,
> although it comes near enough. In fact can do better by using Simplify
> with arather perverse ComplexityFunction tries to make expressions
> more "complex" rather than simpler: (the resulting function should be
> called Complexify but unfortunately thsis word is already reserved for
> a different meaning ;-) )
> Simplify[Log[(a*b)/c],{a>0,b>
> 0,c>0},ComplexityFunction->(1/LeafCount[#]&)]
>
> log(a)+log(b)-log(c)
PowerExpand[Log[(a*b)/c]]
-> Log[a] + Log[b] - Log[c]
without any assumptions...
Klaus G.