Re: Simplifying the exponents

*To*: mathgroup at smc.vnet.net*Subject*: [mg80017] Re: Simplifying the exponents*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Fri, 10 Aug 2007 06:43:07 -0400 (EDT)*Organization*: Uni Leipzig*References*: <f9gv3l$b5e$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, Exp[I (q1 y1 + q2 y2 + q3 y3) - I (qp1 y1 + qp2 y2 + qp3 y3)] /. Exp[a_] :> Exp[Collect[a, {y1, y2, y3}]] will do the first, the second will not work easyly because Mathematica will always simplify Exp[a]*Exp[b] to Exp[a+b] Regards Jens Jung-Tsung Shen wrote: > Hello, I would like to ask a question which I haven't been able to > find a solution that does not need human intervening. > > I would like to simplify the following expression > > Exp[I (q1 y1 + q2 y2 + q3 y3) - I (qp1 y1 + qp2 y2 + qp3 y3)] > > according to y1, y2, and y3 so it would look like > > Exp[I (q1-qp1) y1+ I (q2-qp2) y2 + I (q3-qp3) y3], or > > Exp[I (q1-qp1) y1] * Exp[I (q2-qp2) y2] * Exp[I (q3-qp3) y3] > > How could I achieve this in an efficient way? > > Thanks. > > JT >