Adding new rules to Simplify
- To: mathgroup at smc.vnet.net
- Subject: [mg56311] Adding new rules to Simplify
- From: John Billingham <John.Billingham at Nottingham.ac.uk>
- Date: Fri, 22 Apr 2005 06:22:35 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
I'm trying to teach Mathematica the obvious simplification rules for Jacobi elliptic functions, which i had hoped would be built in! Grumble
Having defined
sn[x_ /; !FreeQ[x, JacobiSN] :=
x /. JacobiSN[u_, m_]-> Sqrt[(1 - JacobiDN[u, m]^2)/m];
sn[x_] := x;
mySimplify =
Simplify[#, TransformationFunctions -> {sn, Automatic}] &;
I find that
mySimplify[1 - (1 - k^2) JacobiSN[p, 1 - k^2]]
gives me
JacobiDN[p, 1 - k^2]^2
as I had hoped, but that the equivalent expression
mySimplify[1 + (-1 + k^2) JacobiSN[p, 1 - k^2]
leaves the formula unsimplified.
What Mathematica subtlety am I missing here??
Thanks,
John
- Follow-Ups:
- Re: Adding new rules to Simplify
- From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
- Re: Adding new rules to Simplify