Ask Your Question
0

Evaluating the error "Can only substitute elements of positive valuation"

asked 2018-05-21 18:26:37 +0100

JHales gravatar image

updated 2018-12-16 18:40:05 +0100

FrédéricC gravatar image

I'm trying to work with sage's weierstrass_p function for elliptic curves, and I'm getting an error that I can't interpret.

This is what I'm running,

E = EllipticCurve('11a1')
WP = E.weierstrass_p()
L = E.lseries()
WP(L(1))

The error I'm getting is "Can only substitute elements of positive valuation"

And I just don't know why sage doesn't want to evaluate the function at the given value. Any thoughts would be really appreciated!

edit retag flag offensive close merge delete

Comments

WP is not a function, but a power series

sage: WP
z^-2 + 31/15*z^2 + 2501/756*z^4 + 961/675*z^6 + 77531/41580*z^8 + 1202285717/928746000*z^10 + 
2403461/2806650*z^12 + 30211462703/43418875500*z^14 + 3539374016033/7723451736000*z^16 + 
413306031683977/1289540602350000*z^18 + O(z^20)
FrédéricC gravatar imageFrédéricC ( 2018-05-22 09:19:03 +0100 )edit

Is there no way to evaluate, even if it's just a numeric approximation the power-series at a value of z?

JHales gravatar imageJHales ( 2018-05-22 16:36:23 +0100 )edit

1 Answer

Sort by » oldest newest most voted
1

answered 2018-05-22 20:46:21 +0100

dan_fulea gravatar image

Is the following numerically good enough?

E  = EllipticCurve('11a1')
L  = E.lseries()
WP = E.weierstrass_p( prec=40 ).laurent_polynomial()
WP( L(1) )

Result:

15.6666666666667
edit flag offensive delete link more

Your Answer

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

Add Answer

Question Tools

1 follower

Stats

Asked: 2018-05-21 18:26:37 +0100

Seen: 445 times

Last updated: May 22 '18