Re: [Help-glpk] Getting more info from presolver

[glpk xypron]

Hello Andrew,

http://www.sce.carleton.ca/faculty/chinneck/docs/InfeasibilityTutorial.pdf
gives an overview of heuristics used by other codes to determine an 
"irreducible infeasible subset" (IIS).

The following paper might be of interest too:
J.W. Chinneck, (1996), "An Effective Polynomial-Time Heuristic for the 
Minimum-Cardinality IIS Set-Covering Problem", Annals of Mathematics and 
Artificial Intelligence, vol. 17, pp. 127-144. 
http://www.springerlink.com/content/50522jj215k26328/

Best regards

Xypron


-------- Original-Nachricht --------
> Datum: Fri, 20 Jun 2008 17:45:34 +0400
> Von: Andrew Makhorin
> An: Joey Rios
> 
> Probably printing information about the row/column, which is found
> infeasible, would be useful. Thank you for your suggestion.
> 
> However, I would like to note that that row/column is the root of
> a tree, where any row/column may cause infeasibility, and it would
> be difficult to track all such rows/columns because of recursive
> nature of the presolving process.
> 
> 
> Andrew Makhorin
> 

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