Opened 11 years ago
Closed 7 years ago
#5392 closed defect (fixed)
relative number field subfield method -- unclear documentation
Reported by: | dmharvey | Owned by: | davidloeffler |
---|---|---|---|
Priority: | major | Milestone: | sage-5.11 |
Component: | number fields | Keywords: | sd51 |
Cc: | Merged in: | sage-5.11.rc0 | |
Authors: | Alejandro Argaez | Reviewers: | Michiel Kosters |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Consider
sage: R.<a> = NumberField(x^4 - 2*x^2 - 1) sage: S.<i> = R.extension(x^2 + 1) sage: S.subfield(a + i/a)
The S.subfield method documentation says that it constructs QQ(alpha), but this is false, I think it constructs R(alpha). In the above example, S.subfield(a + i/a) returns a number field of degree 8 over Q, whereas a + i/a has degree 4 over QQ (the minimal polynomial is x^4 - 4x^2 + 8
).
Attachments (2)
Change History (12)
comment:1 Changed 11 years ago by
- Milestone set to sage-3.4.1
comment:2 Changed 11 years ago by
- Component changed from number theory to number fields
- Owner changed from was to davidloeffler
Changed 7 years ago by
comment:3 Changed 7 years ago by
- Report Upstream set to N/A
- Status changed from new to needs_review
comment:4 Changed 7 years ago by
- Keywords sd51 added
comment:5 Changed 7 years ago by
- Reviewers set to Michiel Kosters
- Status changed from needs_review to positive_review
I happy with changes suggested by Michiel, and he is happy with mine.
comment:6 Changed 7 years ago by
Apply trac_5392_subfield_review.patch after trac_5392.patch
comment:7 Changed 7 years ago by
- Status changed from positive_review to needs_work
The reviewer patch needs a proper commit message, use hg qrefresh -e
for this.
Changed 7 years ago by
comment:8 follow-up: ↓ 9 Changed 7 years ago by
@jdemeyer: is it correct now?
comment:9 in reply to: ↑ 8 Changed 7 years ago by
- Status changed from needs_work to positive_review
Replying to mkosters:
@jdemeyer: is it correct now?
It has a proper commit message now. So assuming this is the same patch, I'll put this to positive review again.
comment:10 Changed 7 years ago by
- Merged in set to sage-5.11.rc0
- Resolution set to fixed
- Status changed from positive_review to closed
patch against sage 5.10