ASKSAGE: Sage Q&A Forum - Individual question feedhttp://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Tue, 22 May 2018 13:46:21 -0500Evaluating the error "Can only substitute elements of positive valuation"http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/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!Mon, 21 May 2018 11:26:37 -0500http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/Comment by JHales for <p>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.</p>
<p>This is what I'm running, </p>
<pre><code>E = EllipticCurve('11a1')
WP = E.weierstrass_p()
L = E.lseries()
WP(L(1))
</code></pre>
<p>The error I'm getting is
"Can only substitute elements of positive valuation"</p>
<p>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!</p>
http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/?comment=42391#post-id-42391Is there no way to evaluate, even if it's just a numeric approximation the power-series at a value of z?Tue, 22 May 2018 09:36:23 -0500http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/?comment=42391#post-id-42391Comment by FrédéricC for <p>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.</p>
<p>This is what I'm running, </p>
<pre><code>E = EllipticCurve('11a1')
WP = E.weierstrass_p()
L = E.lseries()
WP(L(1))
</code></pre>
<p>The error I'm getting is
"Can only substitute elements of positive valuation"</p>
<p>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!</p>
http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/?comment=42387#post-id-42387WP 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)Tue, 22 May 2018 02:19:03 -0500http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/?comment=42387#post-id-42387Answer by dan_fulea for <p>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.</p>
<p>This is what I'm running, </p>
<pre><code>E = EllipticCurve('11a1')
WP = E.weierstrass_p()
L = E.lseries()
WP(L(1))
</code></pre>
<p>The error I'm getting is
"Can only substitute elements of positive valuation"</p>
<p>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!</p>
http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/?answer=42398#post-id-42398Is 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
Tue, 22 May 2018 13:46:21 -0500http://ask.sagemath.org/question/42382/evaluating-the-error-can-only-substitute-elements-of-positive-valuation/?answer=42398#post-id-42398