Can anyone tell me if there is a C routine that I can use to compute the Weierstrass elliptic functions p, p', sigma, and zeta (using either invariants or half-periods)?

(Info on Weierstrass elliptic functions at http://mathworld.wolfram.com/WeierstrassEllipticFunction.html)

Jan M. ('_')

Finding it in C may be too much to hope for!

In the ACM TOMS algorithm collection (here) (http://netlib.bell-labs.com/netlib/toms/), algorithm 549, in Fortran, says that it is a Weierstrass elliptic function. Does this do what you need?

I think that IMSL (here) (http://www.vni.com/products/imsl/) does Weierstrass, and it has a C library, but it was pretty expensive when I last looked.

Good luck!

Thanks, Mr. Press, but the TOMS routines work only for special cases. I was looking for something that will implement the general function.

Worst comes to worst, I'll write the routine myself... oh well.

Jan M. (~_')

P.S. In case the routine I write actually works, can you please include it in future editions of NR? Thanks.

P.S. In case the routine I write actually works, can you please include it in future editions of NR? Thanks.
Actually, the best thing would be if you would let us include it on the NR contributions page at http://www.nr.com/contrib/ . Such contributions also get included in new editions of the Numerical Recipes Code CDROMs.

Cheers,
Bill P.

Just recently I have been able to find something that can resolve this thread I posted quite a long time ago.

I have come across the article "Iterative Method for Calculation of the Weierstrass Elliptic Function" by Coquereaux, Grossman, and Lautrup (IMA J. Numer. Anal., (1990) v. 10, pp. 119-128). I am now trying to translate their ideas into working C code.

Just thought others may be interested...

Jan M. (^_^)