[Help-glpk] Re : Can I adjust the gap in glpsol when I use mathprog?

[Robbie Morrison]

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To:           address@hidden
Subject:      [Help-glpk] Can I adjust the gap in glpsol when I use mathprog?
Message-ID:  <address@hidden>
From:         Rafael Torres <address@hidden>
Date:         Wed, 06 Jun 2012 20:33:44 -0500
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> Hi GLPK team:
>
> I'm wondering if is there a way in order to adjust the
> gap when I'm using mathprog?  I'm just saw an option
> for MIP solver (mipgap tol)
>
> thanks in advance.
>
> Best Regards!!
>
> --
> Rafael Torres
>
> "La luna se puede tomar a cucharadas o como una c?psula cada dos horas..."
> - Jaime Sabines -

Hi Rafael

The wikibook gives an example using '--mingap':

  http://en.wikibooks.org/wiki/GLPK/Using_GLPSOL#Usage

The detailed documentation for GLPSOL options can often
be found in the API manual.

In this case, search on "double_mip_gap":

  (default: 0.0)

  The relative mip gap tolerance. If the relative mip
  gap for currently known best integer feasible
  solution falls below this tolerance, the solver
  terminates the search. This allows obtaining
  suboptimal integer feasible solutions if solving the
  problem to optimality takes too long time.

Note too that the gap is reported during runtime if
suitably small:

  http://en.wikibooks.org/wiki/GLPK/Terminal_output#MIP_branch-and-cut_output

You should only need to do this if your models are taking
too long to run.

HTH, Robbie
---
Robbie Morrison
PhD student -- policy-oriented energy system simulation
Technical University of Berlin (TU-Berlin), Germany
University email (redirected) : address@hidden
Webmail (preferred)           : address@hidden
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