Opened 2 years ago

Closed 20 months ago

#26844 closed defect (duplicate)

Derivative of rational functions

Reported by: caruso Owned by:
Priority: major Milestone: sage-duplicate/invalid/wontfix
Component: algebra Keywords:
Cc: Merged in:
Authors: Reviewers: Marc Mezzarobba
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Status badges


I would say that the following is a bug:

sage: A = PolynomialRing(GF(3), name='t')
sage: K = A.fraction_field()
sage: t = K.gen()
sage: t.derivative(t)
Traceback (most recent call last):
ValueError: cannot differentiate with respect to t

The reason is that the method derivative tries to take the derivative of the numerator with respect to the given variable but the variable here lives in the fraction field and not in the polynomial ring.

Should we fix this?

Change History (4)

comment:1 Changed 21 months ago by bruno

  • Milestone changed from sage-8.5 to sage-duplicate/invalid/wontfix
  • Status changed from new to needs_review

This bug happens to be fixed by #28147.

comment:2 Changed 20 months ago by mmezzarobba

  • Reviewers set to Marc Mezzarobba
  • Status changed from needs_review to positive_review

comment:3 Changed 20 months ago by bruno

Thanks Marc!

comment:4 Changed 20 months ago by chapoton

  • Resolution set to duplicate
  • Status changed from positive_review to closed
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