Re: Collect exponents only
- To: mathgroup at smc.vnet.net
- Subject: [mg101397] Re: [mg101385] Collect exponents only
- From: "David Park" <djmpark at comcast.net>
- Date: Sun, 5 Jul 2009 04:46:21 -0400 (EDT)
- References: <22897006.1246704619067.JavaMail.root@n11>
expr = A Exp[I (x + y) - I x] + A^2 Exp[I (x + y) - I y]; expr /. Exp[s_] :> Simplify[Exp[s]] A^2 E^(I x) + A E^(I y) Collect[expr, A, Simplify] A^2 E^(I x) + A E^(I y) David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ From: Francisco Rojas [mailto:fjrojas at gmail.com] Hello, I was wondering if there's anyway to ask the command Simplify (or maybe some other command) to only collect terms in the exponents of a long expression (which contains complex exponentials by the way) and not perform any other kind of simplification. For example I have an expression like this: A Exp[ I (x+y) - I x] + A^2 Exp[ I (x+y) - I y] ( I is the the imaginary unit ) Mathematica does two simplications here: it simplifies the terms in the exponents and factors out the A giving: A (Exp[ I y] + Exp[I x]) whereas I would like to obtain only the exponents simplification, i.e. A^2 Exp[ I y] + A Exp[ I x] Anybody knows how to do this? Thanks in advance, Francisco