Opened 13 years ago
Closed 11 years ago
#3465 closed defect (wontfix)
Number Field base rings for NumberFieldTower
Reported by: | roed | Owned by: | davidloeffler |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | number fields | Keywords: | relative number fields |
Cc: | craigcitro | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
When creating towers of number fields, the base rings don't behave as I think they should. The following is from the coercion branch (the opposite problem exists in the normal branch).
sage: sage: L.<cuberoot2, zeta3> = CyclotomicField(3).extension(x^3 - 2) sage: type(L) <class 'sage.rings.number_field.number_field.NumberField_relative'> sage: L.ngens() 1 (2 in current Sage, I think it should be 1) sage: L.base_ring() Cyclotomic Field of order 3 and degree 2 (I agree) sage: L.base_field() Cyclotomic Field of order 3 and degree 2 (I agree) sage: L.base() Rational Field (I think it should be Cyclotomic Field of order 3 and degree 2) sage: K.<a, b> = NumberField( [x^2 + x + 1, x^3 + 2] ) sage: K.ngens() 1 (2 in current Sage, I think it should be 2)sage: type(K) <class 'sage.rings.number_field.number_field.NumberField_relative'> sage: K.base_ring() Number Field in b with defining polynomial x^3 + 2 (I think it should be Rational Field) sage: K.base_field() Number Field in b with defining polynomial x^3 + 2 (I think it should be Rational Field) sage: K.base() Rational Field (um... ok, I agree)
Change History (7)
comment:1 Changed 13 years ago by
- Description modified (diff)
comment:2 Changed 13 years ago by
comment:3 Changed 13 years ago by
- Cc craigcitro added
comment:4 Changed 12 years ago by
- Component changed from number theory to number fields
- Owner changed from was to davidloeffler
comment:5 Changed 11 years ago by
- Report Upstream set to N/A
- Status changed from new to needs_review
This ticket has been idle for nearly two years, and moreover it's not really clear to me exactly what the reporter considers to be a bug. Is the suggestion that the objects created via the NumberFieldTower constructor should somehow behave differently from ones created via the extension() method? That sounds like a bad idea to me.
I suggest closing this as wontfix. I'm setting this to "needs review" in order to request a second opinion on my proposal not to fix this.
comment:6 Changed 11 years ago by
- Status changed from needs_review to positive_review
I agree, the result should be homogenenous no matter how you have constructed the field.
I think that the problem is that base had no documentation.
comment:7 Changed 11 years ago by
- Milestone changed from sage-4.5.2 to sage-duplicate/invalid/wontfix
- Resolution set to wontfix
- Status changed from positive_review to closed
Note that this affects the doctests for sage.rings.number_field.RelativeNumberFieldHomset?.list