Ticket #13005 (closed defect: fixed)

Opened 12 months ago

Last modified 11 months ago

"maximum recursion depth exceeded" when doing change_ring(RR) on an elliptic curve

Reported by: was Owned by: cremona
Priority: major Milestone: sage-5.1
Component: elliptic curves Keywords: sd40.5
Cc: Work issues:
Report Upstream: N/A Reviewers: William Stein
Authors: R. Andrew Ohana Merged in: sage-5.1.beta5
Dependencies: Stopgaps:

Description

Behold this bug: 

K.<a> = NumberField(x^2-5)
EllipticCurve(K,[1..5]).change_ring(RR)

BOOM! 

...
  File "coerce_maps.pyx", line 82, in sage.structure.coerce_maps.DefaultConvertMap_unique._call_ (sage/structure/coerce_maps.c:3345)
  File "coerce_maps.pyx", line 77, in sage.structure.coerce_maps.DefaultConvertMap_unique._call_ (sage/structure/coerce_maps.c:3248)
  File "/Users/wstein/sage/build/sage-5.0/local/lib/python2.7/site-packages/sage/rings/complex_field.py", line 286, in _element_constructor_
    if not isinstance(x, (real_mpfr.RealNumber, tuple)):
RuntimeError: maximum recursion depth exceeded while calling a Python object

Attachments

13005.patch Download (2.7 KB) - added by rohana 12 months ago.

Change History

comment:1 Changed 12 months ago by cremona

It's nothing to do with elliptic curves. Try 

sage: K.<a> = NumberField(x^2-5)
sage: RR(K(1))

So the expected "natural" coercion from elements of K to elements of RR is blowing up, instead of using the default embedding.

comment:2 Changed 12 months ago by rohana

  • Keywords sd40.5 added
  • Status changed from new to needs_review
  • Authors set to R. Andrew Ohana

comment:3 follow-up: ↓ 4 Changed 12 months ago by roed

  • Status changed from needs_review to needs_work

Can you add doctests for number fields that already embeds into a real field (possibly of precision different from that of R)?

comment:4 in reply to: ↑ 3 Changed 12 months ago by rohana

  • Status changed from needs_work to needs_review

Replying to roed:

Can you add doctests for number fields that already embeds into a real field (possibly of precision different from that of R)?

Ok, done

comment:5 follow-up: ↓ 6 Changed 12 months ago by ppurka

Can you mention the ticket number as :trac:`#13005` in the documentation?

comment:6 in reply to: ↑ 5 Changed 12 months ago by rohana

Replying to ppurka:

Can you mention the ticket number as :trac:`#13005` in the documentation?

Done

comment:7 Changed 12 months ago by was

Never ever do this: 

            raise TypeError("cannot convert %s to real number"%(self))

Changed 12 months ago by rohana

comment:8 Changed 12 months ago by was

  • Status changed from needs_review to positive_review
  • Reviewers set to William Stein

LGTM

comment:9 Changed 11 months ago by jdemeyer

  • Status changed from positive_review to closed
  • Resolution set to fixed
  • Merged in set to sage-5.1.beta5
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