Opened 10 years ago
Closed 10 years ago
#11218 closed defect (fixed)
factor is broken for polynomials over relative number fields
Reported by: | lftabera | Owned by: | tbd |
---|---|---|---|
Priority: | major | Milestone: | sage-4.7.1 |
Component: | factorization | Keywords: | factorization, tower of number fields |
Cc: | Merged in: | sage-4.7.1.alpha3 | |
Authors: | Francis Clarke | Reviewers: | Luis Felipe Tabera Alonso |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
I suspect this is a regression, but I do not have and old sage copy right now
sage: K=QQ[I]['x,t'] sage: K.inject_variables() Defining x, t sage: f=t^2+1 sage: f.factor() (t + (-I)) * (t + (I)) sage: K=QQ[sqrt(5),I]['t'] sage: K.inject_variables() Defining t sage: f=t^2+1 sage: f.factor() (x + I) * (x - I) sage: prod(f.factor())==f False sage: f.parent() Univariate Polynomial Ring in t over Number Field in sqrt5 with defining polynomial x^2 - 5 over its base field sage: prod(f.factor()).parent() Univariate Polynomial Ring in x over Number Field in sqrt5 with defining polynomial x^2 - 5 over its base field
Factor of uni-variate polynomials in polynomial rings (uni and multivariate) over towers of number fields are broken, since the output variable is always 'x', so it the output is in the wrong ring.
Attachments (1)
Change History (5)
Changed 10 years ago by
comment:1 Changed 10 years ago by
- Status changed from new to needs_review
- Type changed from PLEASE CHANGE to defect
comment:2 Changed 10 years ago by
- Status changed from needs_review to positive_review
The problem has been solved. It was an easy mistake in the code. The doctest shows that the problem has disapeared and the documentation looks god.
Buildbot says that doctest pass.
Positive review.
comment:3 Changed 10 years ago by
- Reviewers set to Luis Felipe Tabera Alonso
comment:4 Changed 10 years ago by
- Merged in set to sage-4.7.1.alpha3
- Resolution set to fixed
- Status changed from positive_review to closed
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In the attached patch this defect is corrected very easily and a doctest is altered to demonstrate that the problem is solved.