Canonical order...
- To: mathgroup at smc.vnet.net
- Subject: [mg54989] Canonical order...
- From: Josef Karthauser <joe at tao.org.uk>
- Date: Wed, 9 Mar 2005 06:34:16 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I'm trying to adjust what Mathematica thinks is canonical order for
a particular function F[], so that orderless functions such as
Times[F[c], F[a], F[b]] automatically gets ordered according to my
specified sort ordering function on F.
I thought that I could do it by tweaking with Order, i.e.
Order[F[a_], F[b_]] := -Order[a,b]
for instance.
I was hoping then that,
Times[F[a],F[b]]
would then become the canonical,
Times[F[b],F[a]],
but this doesn't happen:
: Order[F[a], F[b]]
= -1
: Times[F[b], F[a]]
= F[a] F[b]
: % // FullForm
= Times[F[a], F[b]]
Ok, so it looks like Sort, isn't paying attention to Order[]. Should
it? How do I go about changing the default sort order for a particular
function?
: Sort[{F[a], F[b]}]
= {F[a], F[b]}
Joe
p.s. I've asked for a lot of help recently, but not given much in
return. Many thanks to all of you who are helping me out with this
learning curve! :) You're all stars!
--
Josef Karthauser (joe at tao.org.uk) http://www.josef-k.net/
FreeBSD (cvs meister, admin and hacker) http://www.uk.FreeBSD.org/
Physics Particle Theory (student) http://www.pact.cpes.sussex.ac.uk/
================ An eclectic mix of fact and theory. =================
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