Opened 6 years ago

Closed 16 months ago

#17598 closed defect (fixed)

fixed-mod p-adic integers as polynomial roots

Reported by: gagern Owned by:
Priority: major Milestone: sage-9.0
Component: padics Keywords: padicIMA, padicBordeaux
Cc: jakobkroeker Merged in:
Authors: David Roe Reviewers: Xavier Caruso
Report Upstream: N/A Work issues:
Branch: b070a12 (Commits) Commit: b070a12a9f23f26f934cb99a5f27d55c5ac0889d
Dependencies: Stopgaps:

Description

I think the following should not return an empty list:

sage: cyclotomic_polynomial(3).roots(Zp(739, 566, type="fixed-mod"))
[]

The problem appears to be specific to the fixed-mod type. For capped-rel and capped-abs, two roots are found as expected. So if there is no more elegant solution, one could always compute the result in the capped-abs field and then cast to fixed-mod.

Change History (11)

comment:1 Changed 4 years ago by jakobkroeker

  • Cc jakobkroeker added

comment:2 Changed 4 years ago by chapoton

When computing the roots, one step gives capped-precision.

Then x with capped-precision does not compare == to its image in the same field with fixed-modulus.

So the root is excluded as not being in the given field.

comment:3 Changed 3 years ago by roed

  • Keywords padicIMA added

comment:4 Changed 17 months ago by roed

  • Keywords padicBordeaux added

comment:5 Changed 17 months ago by roed

  • Branch set to u/roed/FMroots

comment:6 Changed 17 months ago by roed

  • Commit set to b070a12a9f23f26f934cb99a5f27d55c5ac0889d
  • Status changed from new to needs_review

New commits:

b070a12Fix some typos and trailing whitespace in padic_generic; change _roots_from_factorization to support fixed mod p-adics

comment:7 Changed 17 months ago by roed

  • Authors set to David Roe

comment:8 Changed 16 months ago by caruso

  • Reviewers set to Xavier Caruso
  • Status changed from needs_review to positive_review

Thanks for fixing this bug.

comment:9 Changed 16 months ago by chapoton

  • Milestone changed from sage-6.5 to sage-8.9

comment:10 Changed 16 months ago by chapoton

  • Milestone changed from sage-8.9 to sage-9.0

moving milestone to 9.0 (after release of 8.9)

comment:11 Changed 16 months ago by vbraun

  • Branch changed from u/roed/FMroots to b070a12a9f23f26f934cb99a5f27d55c5ac0889d
  • Resolution set to fixed
  • Status changed from positive_review to closed
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