Re: Separating constants from nonconstants in an expression

*To*: mathgroup at smc.vnet.net*Subject*: [mg52434] Re: [mg52423] Separating constants from nonconstants in an expression*From*: yehuda ben-shimol <benshimo at bgu.ac.il>*Date*: Sat, 27 Nov 2004 01:40:29 -0500 (EST)*References*: <200411261120.GAA05129@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

The simplest way I can think of (there are few ways to do that) is as follows expr := (4 Pi k1 x k2 y)/(12 k3 t k4 u) Coefficient[expr/.{t->1/w,u->1/z},x y w z] notice that neither Coefficient[expr, x y /u /t ] nor Coefficient[expr, x y /(u t)] work Another way is Fold[Coefficient,expr,{x,y,1/u,1/t}] yehuda Nicolas Girard wrote: >Hi, >given any expression like > > expr := (4 Pi k1 x k2 y)/(12 k3 t k4 u) > >and knowing that k1...k4 are constants, how could I separate these terms >from the non constant ones, i.e. ending up with > > Pi k1 k2 x y > -------- . --- > 3 k3 k4 t u > >? I've looked into the manual & browsed this newsgroup, but didn't find a >clue... > >Many thanks in advance ! >Nicolas > > > >

**References**:**Separating constants from nonconstants in an expression***From:*Nicolas Girard <nicolas.girard@strasbourg.fr>