Opened 15 years ago

Closed 15 years ago

## #2496 closed defect (fixed)

# bug in introspection (probably easy to fix)

Reported by: | William Stein | Owned by: | tba |
---|---|---|---|

Priority: | major | Milestone: | sage-3.0.2 |

Component: | documentation | Keywords: | |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

Report Upstream: | N/A | Work issues: | |

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

See near the bottom below. In particular the `X.points??`

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.

> > 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 #

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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.