Opened 13 years ago
Closed 12 years ago
#8446 closed defect (fixed)
avoid 0^0 in number fields
Reported by: | Robert Miller | Owned by: | David Loeffler |
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Priority: | major | Milestone: | sage-4.4 |
Component: | number fields | Keywords: | |
Cc: | John Cremona | Merged in: | sage-4.4.alpha2 |
Authors: | Robert Miller | Reviewers: | David Loeffler |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
In the case of a trivial number field, such as
K.<a> = NumberField(polygen(QQ))
the Selmer group function doesn't work, since the generator a
of the number field is 0, and when we're constructing polynomials we use the form coeff*a**i
. However, if i==0
, we get an ArithmeticError
since Sage does not have conventions for 0^0
.
I found several places where this comes up, and I've fixed them where I can.
Attachments (2)
Change History (9)
comment:1 Changed 13 years ago by
Status: | new → needs_review |
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comment:2 Changed 13 years ago by
Description: | modified (diff) |
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Summary: | avoid 0^0 in Selmer groups of number fields → avoid 0^0 in number fields |
Changed 13 years ago by
Attachment: | trac_8446.patch added |
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Changed 12 years ago by
Attachment: | trac_8446_microfix.patch added |
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comment:3 Changed 12 years ago by
Looks fine, and all doctests pass. FWIW, I think that there should be a doctest in _S_class_group_and_units
, not just in selmer_group
, as that's where the problem actually occurs; and the docstring for selmer_group
contains the literal string \t
so it should be a raw string. Hence the tiny second patch. I'm giving this a positive review modulo that, so please set it to positive review if you're happy with the second patch.
BTW, I tried using this for some some relative extensions and discovered two separate new bugs in the process, #8721 and #8722. Neither of these actually has anything to do with this patch as such, it's preexisting brokenness. I know what's causing #8722; I'll upload a patch shortly -- any chance you could review it for me?
comment:4 Changed 12 years ago by
Reviewers: | → David Loeffler |
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Status: | needs_review → positive_review |
comment:5 Changed 12 years ago by
Re #8722 - I will be happy to review it eventually, but no guarantees at this very moment, since I'm finishing up my dissertation and preparing to defend it next month.
comment:7 Changed 12 years ago by
Merged in: | → sage-4.4.alpha2 |
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Resolution: | → fixed |
Status: | positive_review → closed |
Merged into 4.4.alpha2:
- trac_8446.patch
- trac_8446_microfix.patch
apply over previous patch