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

asked 2018-05-21 18:26:37 +0200

JHales gravatar image

updated 2018-12-16 18:40:05 +0200

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()

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!

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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 +0200 )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 +0200 )edit

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answered 2018-05-22 20:46:21 +0200

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) )


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Asked: 2018-05-21 18:26:37 +0200

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Last updated: May 22 '18