Opened 14 years ago

Closed 20 months ago

#28 closed enhancement (migrated)

getDualRays maxNumRays, but only 1 in CLP/CPX

Reported by: mgalati Owned by: mjs
Priority: minor Milestone:
Component: Osi Base Class Version: 0.95.2
Keywords: dual ray Cc: magh@…, tkr2@…

Description (last modified by lou)

In both OsiClp and OsiCpx, getDualRays takes arg=maxNumRays, but only returns 1 dual ray. Can the solvers provide more than one? If so, can this be implemented (this would be nice)? If not, should there be a maxNumRays argument at all? It seems misleading.

Change History (2)

comment:1 Changed 12 years ago by lou

  • Description modified (diff)
  • Priority changed from major to minor

Just finished crafting the dylp equivalent, so I can offer some observations. It's not particularly hard to find all rays at the vertex where unboundedness is detected. Finding other rays, if they exist, amounts to walking the vertices of the polytope. The computational cost would be fairly high.

comment:2 Changed 20 months ago by stefan

  • Cc changed from magh@lehigh.edu; tkr2@lehigh.edu to magh@lehigh.edu, tkr2@lehigh.edu
  • Resolution set to migrated
  • Status changed from new to closed

This ticket has been migrated to GitHub and will be resolved there: https://github.com/coin-or/Osi/issues/28

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