[Bonmin] Feasibility in BONMIN

Novalio Daratha novatha at gmail.com
Wed Jul 31 07:47:00 EDT 2013


Dear All,

I am trying to solve an MINLP using bonmin. It reported the MINLP as
infeasible problem while during the iterations I see some feasible
solutions. My question are:

1.  why does bonmin conclude it as infeasible problem?
2.  why not it gives the feasible solution even if it is not locally
optimal?

For your consideration, I put an example of bonmin output at the end of
this email. (bb_log_level 1).


I am thankful for your kind attention and help.

Sincerely Yours,

Novalio Daratha
PhD student
IIT Roorkee
India



Bonmin 1.5.2 using Cbc 2.7.6 and Ipopt 3.10.2
bonmin:

******************************************************************************
This program contains Ipopt, a library for large-scale nonlinear
optimization.
 Ipopt is released as open source code under the Eclipse Public License
(EPL).
         For more information visit http://projects.coin-or.org/Ipopt
******************************************************************************

NOTE: You are using Ipopt by default with the MUMPS linear solver.
      Other linear solvers might be more efficient (see Ipopt
documentation).


NLP0012I
              Num      Status      Obj             It       time
      Location
NLP0014I             1      FAILED 0.0044821868     3000 8.388
NLP0014I             1      FAILED 0.0044678956     3000 7.652   resolve
robustness
NLP0014I             3         OPT 0.0041219542     1030 3.17
NLP0012I
              Num      Status      Obj             It       time
      Location
NLP0014I             1      INFEAS 1       54 0.144
NLP0014I             4      FAILED 1.2200549     3000 7.826
NLP0014I             5      FAILED 1.2400101     3000 8.146
NLP0014I             6      FAILED 1.2413622     3000 8.007
NLP0014I             7      FAILED 1.2398611     3000 7.769
NLP0014I             8      FAILED 0.03787479     3000 7.779
NLP0014I             9      FAILED -0.070294006     3000 7.33
NLP0014I            10      FAILED 0.0044563366     3000 7.775
NLP0014I            11      FAILED -0.070344772     3000 7.33
NLP0014I            12      FAILED 1.2242858     3000 7.964
NLP0014I            13      FAILED -0.070401127     3000 7.064
NLP0014I            14      FAILED 1.2470022     3000 7.639
NLP0014I            15      FAILED -0.070728211     3000 6.996
NLP0014I            16         OPT 0.0041219556      945 2.374
NLP0014I            17      FAILED -0.070781423     3000 6.949
NLP0014I            18      FAILED 0.0044845077     3000 7.292
NLP0014I            19      FAILED -0.069781992     3000 7.329
NLP0014I            20      FAILED 0.0045109264     3000 7.359
NLP0012I
              Num      Status      Obj             It       time
      Location
NLP0014I            21      FAILED -0.070408086     3000 7.094
NLP0014I            22      FAILED 0.0045273783     3000 7.419
NLP0014I            23      FAILED -0.070202589     3000 7.304
NLP0014I            24      FAILED 0.0054378863     3000 7.413
NLP0014I            25      FAILED -0.068064574     3000 7.261
NLP0014I            26         OPT 0.0041219556        6 0.012
NLP0014I            27      INFEAS 0.022268486       32 0.074
NLP0014I            28         OPT 0.0041219556        6 0.012
NLP0014I            29      FAILED 1.241151     3000 7.391
NLP0014I            30      FAILED 0.018211754     3000 7.548
NLP0014I            31         OPT 0.0041219556      803 1.956
NLP0014I            32      FAILED -0.15280958     3000 7.369
NLP0014I            33         OPT 0.0041219545        9 0.03
NLP0014I            34      FAILED -0.07020253     3000 7.219
NLP0014I            35         OPT 0.0041219549        7 0.022
NLP0014I            36      FAILED -0.069945526     3000 7.181
NLP0014I            37         OPT 0.0041219552       11 0.038
NLP0014I            38      FAILED -0.070313109     3000 7.356
NLP0014I            39         OPT 0.0041219556       14 0.031
NLP0014I            40      FAILED -0.070260101     3000 7.076
NLP0012I
              Num      Status      Obj             It       time
      Location
NLP0014I            41         OPT 0.0041219556        7 0.016
NLP0014I            42      FAILED -0.070746826     3000 7.126
NLP0014I            43         OPT 0.0041219556        6 0.013
NLP0014I            44      FAILED -0.070402666     3000 7.196
NLP0014I            45         OPT 0.0041219556        6 0.013
NLP0014I            46      FAILED -0.070522355     3000 7.377
NLP0014I            47         OPT 0.0041219556        6 0.013
NLP0014I            48      FAILED -0.069211894     3000 7.122
NLP0014I            49         OPT 0.0041219556        6 0.012
NLP0014I            50      FAILED -0.053808856     3000 6.91
NLP0014I            51         OPT 0.0041219556        6 0.013
NLP0014I            52      INFEAS 0.016728388       36 0.086
NLP0014I            53         OPT 0.0041219556        6 0.013
NLP0014I            54      FAILED 1.2291456     3000 7.679
NLP0014I            55      FAILED 0.0045429683     3000 7.632
NLP0014I            56         OPT 0.0041219556        6 0.013
NLP0014I            57      INFEAS 0.010787243       32 0.075
NLP0014I            58         OPT 0.0041219556        6 0.013
NLP0014I            59      FAILED 1.1645369     3000 8.174
NLP0014I            60      FAILED 0.0063708004     3000 7.581
NLP0012I
              Num      Status      Obj             It       time
      Location
NLP0014I            61         OPT 0.0041219492       20 0.062
NLP0014I            62      INFEAS 0.0046434659       38 0.089
NLP0014I            63         OPT 0.0041219492       20 0.063
NLP0014I            64      INFEAS 0.99998118      703 1.888
NLP0014I            65      FAILED 1.2612585     3000 8.095
NLP0014I            66      FAILED 1.2456221     3000 7.746
Cbc0001I Search completed - best objective 1e+050, took 3038 iterations and
0 nodes (299.17 seconds)
Cbc0032I Strong branching done 29 times (116699 iterations), fathomed 0
nodes and fixed 5 variables
Cbc0035I Maximum depth 0, 0 variables fixed on reduced cost
NLP0014I            67      FAILED -0.14257739     3000 7.17

        "Finished"

bonmin: Infeasible problem
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