Changes between Version 75 and Version 81 of Ticket #10039

04/02/11 03:09:05 (8 years ago)

I finally got the problem with the maximize/minimize doctest failure. If the linear function is not bounded on the polyhedron then it doesn't make sense to ask for whether its a maximum or minimum. And PPL then does not return a consistent value for the corresponding field.

In the attached patch I changed return value of the maximize/minimize methods to only return {'bounded':False} if the linear program is unbounded, since all other dictionary entries are not well-defined in that case. If the linear program is bounded then the returned dictionary is the same as before and contains information about the sup/inf value, whether it is a maximum, and where it is attained.

The new patch trac_10039_ppl_fix_extremize.patch needs to be applied on top of trac_10039_parma_polyhedra_library.patch, see also the ticket description. The new patch needs review.


  • Ticket #10039

    • Property Status changed from needs_work to needs_review
    • Property Merged in changed from sage-4.7.alpha3 to
  • Ticket #10039 – Description

    v75 v81  
    2222  * copy the ppl spkg to `$SAGE_ROOT/spkg/standard`
    2323  * apply [attachment:trac_10039_parma_polyhedra_library.patch] to the Sage library
     24  * apply [attachment:trac_10039_ppl_fix_extremize.patch] to the Sage library
    2425  * apply [attachment:10039_manifest.patch] to the Sage library
    2526  * apply [attachment:trac_10039_root_repo.patch] the sage root repository