Opened 10 years ago

Closed 10 years ago

#10799 closed enhancement (fixed)

Solved the problem to compute resultants on certain variable orders

Reported by: mmarco Owned by: AlexGhitza
Priority: major Milestone: sage-4.7
Component: algebra Keywords: resultant
Cc: Merged in: sage-4.7.alpha5
Authors: Miguel Marco Reviewers: Simon Spicer
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

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Description

for univariate polynomial rings over other polynomial rings, the .resultant() method might fail if the variables are not ordered in a 'good' way (i.e. following the PARI convention). This also affects the discriminant method (which calls resultant)

Here is a patch to detect these cases and do the corresponding computation in a bigger multivariate ring (which is handled by Singular).

Attachments (1)

trac_10799_resultant_fix.patch (2.7 KB) - added by mmarco 10 years ago.

Download all attachments as: .zip

Change History (4)

Changed 10 years ago by mmarco

comment:1 Changed 10 years ago by spice

  • Reviewers set to Simon Spicer
  • Status changed from new to needs_review

comment:2 Changed 10 years ago by spice

  • Milestone set to sage-4.7
  • Status changed from needs_review to positive_review

Reviewed; all checks out.

Note that this fixes resultant() for polynomial rings over [polynomial rings over exact fields]; resultant() is *not* implemented when the base field is RDF or CDF. I'll open a new ticket to try implement this.

comment:3 Changed 10 years ago by jdemeyer

  • Merged in set to sage-4.7.alpha5
  • Resolution set to fixed
  • Status changed from positive_review to closed
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