Sage: Ticket #2496: bug in introspection (probably easy to fix)
https://trac.sagemath.org/ticket/2496
<p>
See near the bottom below. In particular the <code>X.points??</code> input
should fail gracefully rather than going boom with an eval error. Closing
this ticket does not necessarily mean fixing anything more than making this
fail gracefully.
</p>
<pre class="wiki">>
> I had a Sage worksheet that created an Elliptic curve
> (E=EllipticCurve([0,17]))
> and then invoked E.rational_points(10).
> The code has obviously changed as it now expects
> different parameters and needs to be E.rational_points(bound=10).
> The real problems is I no longer get all the rational points. Maybe
> the
> definition of bound has changed? I had assumed it was a logarithmic
> bound on the points, but I get only the first few points (max X=4).
>
> I then tried to follow through the code and it's changed a lot since I
> first looked
> at it. rational_points() is now defined in .../schemes/generic/
> algebraic_schemes
> and I'm unable to figure out where to go from there. The code reads:
>
> ...
> if F == None:
> F = self.base_ring()
> X = self(F)
> ...
> return X.points(bound)
>
> Substituting the first part into my worksheet, with substituting E for
> self, I get
> X is Abelian group of points on Elliptic Curve defined by y^2 = x^3 +
> 17
> over Rational Field.
>
> Next I try:
> X.points??
>
> and get
> ---------------------
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> File "/home/bill/.sage/sage_notebook/worksheets/bill/5/code/16.py",
> line 6, in <module>
> print _support_.source_code("", globals())
> File "/sage/current/local/lib/python2.5/site-packages/sage/server/
> support.py", line 154, in source_code
> obj = eval(s, globs)
> File "<string>", line 0
>
> ^
> SyntaxError: unexpected EOF while parsing
> ----------------------
> Not much help there...
> Is this a bug, two bugs, or am I just being my usual stupid self?
>
You score +1 for at least one bug (the second one). The first
regarding the bound is *probably* related to changes John Cremona
made to elliptic curves, and I hope he will comment on them soon.
I've made your second bug above trac #
</pre>en-usSagehttps://trac.sagemath.org/chrome/site/logo_sagemath_trac.png
https://trac.sagemath.org/ticket/2496
Trac 1.1.6wasSun, 11 May 2008 06:12:05 GMTstatus changed; resolution set
https://trac.sagemath.org/ticket/2496#comment:1
https://trac.sagemath.org/ticket/2496#comment:1
<ul>
<li><strong>status</strong>
changed from <em>new</em> to <em>closed</em>
</li>
<li><strong>resolution</strong>
set to <em>fixed</em>
</li>
</ul>
<p>
This is already fixed. First, I can't figure out how to replicate any sort of X.points?? problem. For me that works just fine. Also, the questionable eval above in the traceback is as of sage-3.0.1 already wrapped in a try/except block.
</p>
Ticket