[Coin-symphony] warmstarting
Ted Ralphs
tkralphs at lehigh.edu
Mon Feb 19 13:39:05 EST 2007
Very strange. I don't know what could have changed to cause that. Could
you file a bug report with the MPS file attached and also note the
specific version of the code you are using and the version of the code
you were using when it worked fine?
Cheers,
Ted
Goehring wrote:
> Hi everyone,
>
> I am solving a MILP keeping the warm start manipulationg the objective
> function and solving from warm start. This used to wrok fine. But now
> the objective value does not change any more.
>
> Has the warmstarting routine changed?
>
> Parameters are set as the following:
>
> setSymParam(OsiSymKeepWarmStart,true);
> setSymParam(OsiSymDoReducedCostFixing,false);
>
> Here is the output of my program:
> ------------------------------------
>
> mipSolver->getObjCoefficients()[3]-3.06
> mipSolver->getObjCoefficients()[14]4
> Solving...
>
> ****************************************************
> * Now processing NODE 0 LEVEL 0 (from TM)
> ****************************************************
>
> Diving set to 2
>
>
>
> **** Starting iteration 1 ****
>
> The LP value is: 17527.748 [0,89]
>
> Now displaying the relaxed solution ...
> Receiving/creating cuts...
>
> Cuts in the local pool: 2
>
> Number of cuts added to the problem: 2
>
> In iteration 1, before calling branch()
> ... 2 violated cuts were added
> Continue with this node. 2 cuts added alltogether in iteration 1
>
>
>
> **** Starting iteration 2 ****
>
> The LP value is: 17527.748 [0,2]
>
> Now displaying the relaxed solution ...
> Row effectiveness: rownum: 104 ineff: 0 deletable: 0
>
> Receiving/creating cuts...
>
> Cuts in the local pool: 0
>
>
> In iteration 2, before calling branch()
> ... no cuts were added.
> Now displaying final relaxed solution...
>
> [17464.416, 0,1] [17527.748, 0,4]
> Decided to dive...
> *************************************************
> * Now processing NODE 2 LEVEL 1
> *************************************************
>
>
>
> **** Starting iteration 3 ****
>
> The LP value is: 17527.748 [0,0]
>
>
> ****** Found Better Feasible Solution !
> ****** Cost: 17527.748238
>
> fathoming node (no more cols to check)
>
> ++++++++++++++++++++++++++++++++++++++++++++++++++
> + TM: Pruning NODE 1 LEVEL 1 instead of sending it.
> ++++++++++++++++++++++++++++++++++++++++++++++++++
>
> ****************************************************
> * Optimal Solution Found *
> * Now displaying stats and best solution found... *
> ****************************************************
>
> ======================= CP Timing ===========================
> Cut Pool 0.000
> ====================== LP/CG Timing =========================
> LP Solution Time 0.011
> Variable Fixing 0.000
> Pricing 0.000
> Strong Branching 0.004
> Separation 0.014
> Total User Time 0.029
> Total Wallclock Time 0.031
>
> ====================== Statistics =========================
> Number of created nodes : 3
> Number of analyzed nodes: 2
> Depth of tree: 1
> Size of the tree: 3
> Number of Chains: 1
> Number of Diving Halts: 0
> Number of cuts in cut pool: 0
> Upper Bound in Root: 17527.748
>
> Solution Found: Node 2, Level 1
> Solution Cost: 17527.748
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> User indices and values of nonzeros in the solution
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> 4 728.390
> 9 110.100
> 10 3.000
> 11 8.601
> 14 380.222
> 27 20.000
> 28 20.000
> 29 20.000
> 30 20.000
> 31 20.000
> 32 20.000
> 33 20.000
> 34 20.000
> 35 20.000
> 36 20.000
> 37 20.000
> 38 20.000
> 45 0.826
> 46 34.598
> 47 20.000
> 48 20.000
> 49 38.616
> 50 53.519
> 51 139.000
> 52 139.000
> 53 139.000
> 54 108.625
> 55 129.666
> 56 58.584
> 57 30.097
> 58 600.000
> 59 3.000
> 83 10.000
> 84 1.000
> 159 0.277
> 183 0.469
> 205 0.357
> 210 0.669
> 214 0.248
> 225 2.411
> 231 1.266
> 232 1.075
> 233 2507.884
> 234 1130.479
> 235 1505.256
> 236 456.777
> 237 1505.256
> 238 14792.563
>
> solution.getObjCoefficients()[3]-3.06
> solution.getObjCoefficients()[14]4
> ObjValue with SYMPHONY: 17527.748238
> mipSolver->getObjCoefficients()[3]-1.2
> mipSolver->getObjCoefficients()[14]-8
> Solving...
>
>
> ****************************************************
> * Optimal Solution Found *
> * Now displaying stats and best solution found... *
> ****************************************************
>
> ======================= CP Timing ===========================
> Cut Pool 0.000
> ====================== LP/CG Timing =========================
> LP Solution Time 0.000
> Variable Fixing 0.000
> Pricing 0.000
> Strong Branching 0.000
> Separation 0.000
> Total User Time 0.000
> Total Wallclock Time 0.000
>
> ====================== Statistics =========================
> Number of created nodes : 3
> Number of analyzed nodes: 2
> Depth of tree: 1
> Size of the tree: 3
> Number of Chains: 1
> Number of Diving Halts: 0
> Number of cuts in cut pool: 0
> Upper Bound in Root: 17527.748
>
> Solution Found: Node 2, Level 1
> Solution Cost: 17527.748
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> User indices and values of nonzeros in the solution
> +++++++++++++++++++++++++++++++++++++++++++++++++++
> 4 728.390
> 9 110.100
> 10 3.000
> 11 8.601
> 14 380.222
> 27 20.000
> 28 20.000
> 29 20.000
> 30 20.000
> 31 20.000
> 32 20.000
> 33 20.000
> 34 20.000
> 35 20.000
> 36 20.000
> 37 20.000
> 38 20.000
> 45 0.826
> 46 34.598
> 47 20.000
> 48 20.000
> 49 38.616
> 50 53.519
> 51 139.000
> 52 139.000
> 53 139.000
> 54 108.625
> 55 129.666
> 56 58.584
> 57 30.097
> 58 600.000
> 59 3.000
> 83 10.000
> 84 1.000
> 159 0.277
> 183 0.469
> 205 0.357
> 210 0.669
> 214 0.248
> 225 2.411
> 231 1.266
> 232 1.075
> 233 2507.884
> 234 1130.479
> 235 1505.256
> 236 456.777
> 237 1505.256
> 238 14792.563
>
> solution.getObjCoefficients()[3]-1.2
> solution.getObjCoefficients()[14]-8
> ObjValue with SYMPHONY: 17527.748238
> ----------------------------------
>
> Thanks,
>
> Lutz
>
>
> --
> Lutz Göhring
> Scientific Assistant
>
> with Prof. Thomas Berger
>
> Professur (i.V.) für Ökonomik der Landnutzung in den Tropen und Subtropen
> (Professorship (p.p.) for Land Use Economics in the Tropics and
> Subtropics)
> Institute for Agricultural Economics and Social Sciences in the Tropics
> and Subtropics,
> University of Hohenheim, Stuttgart
>
> e-mail: lutz.goehring at uni-hohenheim.de <mailto:lutz.goehring at uni-hohenheim.de>
> Tel.: +49-711-459-23615
>
>
> ------------------------------------------------------------------------
>
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--
Dr. Ted Ralphs
Associate Professor
Industrial and Systems Engineering
Lehigh University
(610)758-4784
tkralphs at lehigh.edu
www.lehigh.edu/~tkr2
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