Opened 17 months ago
Last modified 17 months ago
#27012 needs_work enhancement
Add construction method to function fields
Reported by: | gh-BrentBaccala | Owned by: | |
---|---|---|---|
Priority: | minor | Milestone: | sage-pending |
Component: | algebra | Keywords: | function field |
Cc: | Merged in: | ||
Authors: | Brent Baccala | Reviewers: | |
Report Upstream: | N/A | Work issues: | |
Branch: | public/27012 (Commits) | Commit: | 62a80275e753308a38da35e2fbc73f2e97dadb26 |
Dependencies: | Stopgaps: |
Description (last modified by )
This ticket enhances the function field code to add a construction functor and support the construction
method:
sage: K.<x> = FunctionField(QQ) sage: K.construction() (FunctionField Fraction Field of Univariate Polynomial Ring in x over Rational Field) sage: from sage.rings.function_field.function_field import FunctionFieldFunctor sage: R.<x> = QQ[] sage: FunctionFieldFunctor()(Frac(R)) Rational function field in x over Rational Field
Change History (8)
comment:1 Changed 17 months ago by
- Branch set to public/27012
- Commit set to 62a80275e753308a38da35e2fbc73f2e97dadb26
- Dependencies set to #22982
comment:2 Changed 17 months ago by
- Dependencies #22982 deleted
- Status changed from new to needs_review
Don't think this needs 22892 as a dependency; it seems to commit fine with 8.5
as a base.
comment:3 Changed 17 months ago by
- Description modified (diff)
comment:4 Changed 17 months ago by
I'm not sure where FunctionFieldFunctor
should go. Right now, it's in function_field.py
in the src/sage/rings/function_field
directory.
Perhaps we should add a new file in that directory called functors.py
? There's going to be at least one more ConstructionFunctor
in the function field code, for constructing spaces of differentials.
comment:5 follow-up: ↓ 6 Changed 17 months ago by
While your patch looks sensible to me, that's not how things currently work for number fields. Instead, number fields are constructed directly from their base field by an AlgebraicConstructionFunctor
. Can you explain why you are deviating from that model? (This may be a stupid question, I basically don't know anything about function fields.) And if your approach is better, should we use it from number fields too?
Also, you may want to add a couple of example of new coercions discovered thanks to the new construction, if there are any.
comment:6 in reply to: ↑ 5 Changed 17 months ago by
Replying to mmezzarobba:
While your patch looks sensible to me, that's not how things currently work for number fields. Instead, number fields are constructed directly from their base field by an
AlgebraicConstructionFunctor
. Can you explain why you are deviating from that model? (This may be a stupid question, I basically don't know anything about function fields.) And if your approach is better, should we use it from number fields too?
I don't know if it's any better this way.
Also, you may want to add a couple of example of new coercions discovered thanks to the new construction, if there are any.
Well, the coercions I wanted it to discover, it couldn't, so I ended up coding them by hand (Trac #26993). I created this ticket because I didn't want to just throw this code away, but I don't know if it does anything useful.
comment:7 Changed 17 months ago by
- Milestone changed from sage-8.6 to sage-8.7
Retarging tickets optimistically to the next milestone. If you are responsible for this ticket (either its reporter or owner) and don't believe you are likely to complete this ticket before the next release (8.7) please retarget this ticket's milestone to sage-pending or sage-wishlist.
comment:8 Changed 17 months ago by
- Milestone changed from sage-8.7 to sage-pending
- Status changed from needs_review to needs_work
New commits:
Trac #27012: add construction method to FunctionField's