Ask Your Question
2

Evaluating values of the Weierstrass $\wp$-function

asked 2013-08-06 04:39:19 -0500

Blackadder gravatar image

I would like to know how can we evaluate the Weierstrass $\wp$-functions. That is, I would like to find $\wp(\theta,\omega,i\omega)$ for some $\theta,\omega\in\mathbb{R}$.

I'm only able to find a function which outputs the Laurent series of the Weierstrass $\wp$-function when an elliptic curve has been entered. Should I evaluate that laurent series?

edit retag flag offensive close merge delete

1 answer

Sort by ยป oldest newest most voted
2

answered 2013-08-07 04:29:35 -0500

Luca gravatar image

The function weierstrass_p() of EllipticCurve returns the Laurent expansion of $\wp$ at the origin, hence evaluating it only gives a reasonable approximation near it.

Nothing comes to my mind to do this kind of numerical evaluation straightforwardly in Sage. If you have access to Maple, you could give a shot at the NumGFun package, part of the AlgoLib library http://algo.inria.fr/libraries/. It has support for the numerical evaluation of functions satisfying linear differential equations with polynomial coefficients.

The author of NumGFun gave a talk on it at Sage Days 49 http://www.marc.mezzarobba.net/#expose-sd49. As you can read in the slides, nothing of it is already in Sage, but there are plans for the close future. See, for example, http://trac.sagemath.org/ticket/14996, which will add functionality similar to what you need.

edit flag offensive delete link more

Comments

The Jacobi elliptic functions in #14996 are already in Sage, the patch just improves them.

Eviatar Bach gravatar imageEviatar Bach ( 2013-08-07 19:45:41 -0500 )edit

Nice, I didn't know that. Then you may try using the formulas given here: <http://en.wikipedia.org/wiki/Weierstrass%27s_elliptic_functions#Relation_to_Jacobi_elliptic_functions></p<>>

Luca gravatar imageLuca ( 2013-08-09 05:04:27 -0500 )edit

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 2013-08-06 04:39:19 -0500

Seen: 158 times

Last updated: Aug 07 '13