complex coefficients and rules...
- To: mathgroup at smc.vnet.net
- Subject: [mg28203] complex coefficients and rules...
- From: Richard Easther <easther at physics.columbia.edu>
- Date: Wed, 4 Apr 2001 04:13:25 -0400 (EDT)
- Organization: Inst. for Strings, Cosmology and Astroparticle Physics (ISCAP)
- Sender: owner-wri-mathgroup at wolfram.com
Hi, 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? Richard