Re: complex coefficients and rules...

*To*: mathgroup at smc.vnet.net*Subject*: [mg28215] Re: [mg28203] complex coefficients and rules...*From*: BobHanlon at aol.com*Date*: Thu, 5 Apr 2001 03:00:29 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

y /: Conjugate[y] = y; Conjugate[Exp[-4*I*y]] E^(4*I*y) Bob Hanlon In a message dated 2001/4/4 4:33:54 AM, easther at physics.columbia.edu writes: >I am having some trouble applying some simple rules to complex >expressions. > >For instance, > > Exp[-4 I y] /. I-> -I > >yields > > Exp[-4 I y] > >This seemed a bit odd, so I looked at the "full form" and found, > >Power[E, Times[Complex[0, -4], y]] > >However, trying the match > > Exp[-4 I y] /. a_ I -> -a I > >doesn't work either, since FullForm[a I ] is Times[Complex[0, -1], a] >and so the patterns do not match. > >All I want is a simple complex conjugate (the Conjugate function does >not assume that y is real), that maps I->-I. The more tricky > > Exp[-4 I y] /. Complex[a_ ,b_] -> Complex[a,-b] > >does work, but it is seems a little cumbersome. > >In any case my question is: is there a general way to avoid having to do >this, or is Mathematica always going to assume that any algebraic >constant is potentially complex? >