Decision Optimization

Decision Optimization

Delivers prescriptive analytics capabilities and decision intelligence to improve decision-making.


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  • 1.  question about cplex.tilim parameter

    Posted 09/10/12 06:32 PM

    Originally posted by: getamail77


    hi, i have a question about cplex.tilim parameter.

    I set cplex.tilim = 360 seconds, thinking that would restrict the cplex to stop at 360 seconds.

    It works for some. But for others, from the log, it shows that cplex output the time statistics at around 360 seconds, and then continue to run, until another 360 seconds passed, and sometimes there is a 3rd 360 seconds.

    I thought by setting cplex.tilim = 360, user can specify the global time spent by cplex. It is really confusing to me. Is this something possibly related to multiple threads in CPLEX?

    thanks a lot!

    java 1495 848 20775.5919 1174 19970.0000 20793.5611 1112580 4.12%
    java 1587 929 20270.7092 597 19970.0000 20793.5611 1176107 4.12%

    java GUB cover cuts applied: 262
    java Clique cuts applied: 675
    java Cover cuts applied: 3184
    java Implied bound cuts applied: 2
    java Flow cuts applied: 4
    java Mixed integer rounding cuts applied: 233
    java Zero-half cuts applied: 101
    java Gomory fractional cuts applied: 78

    java Root node processing (before b&c):
    java Real time = 21.66
    java Parallel b&c, 16 threads:
    java Real time = 337.47
    java Sync time (average) = 10.30
    java Wait time (average) = 0.00
    java
    java Total (root+branch&cut) = 359.13 sec.

    java Nodes Cuts/
    java Node Left Objective IInf Best Integer Best Bound ItCnt Gap

    java 1594 958 20623.9810 917 19970.0000 20793.5611 1207706 4.12%
    java Elapsed real time = 4.52 sec. (tree size = 68.83 MB, solutions = 0)
    java 1595 958 20654.4786 481 19970.0000 20793.5611 1207737 4.12%
    java 1597 959 20644.3186 883 19970.0000 20790.5193 1207816

    .........
    #CPLEXOptimizers
    #DecisionOptimization


  • 2.  Re: question about cplex.tilim parameter

    Posted 09/11/12 05:33 PM

    Originally posted by: SystemAdmin


    The TiLim parameter limits the time spent on any one call to solve(). If you call solve() multiple times, each call gets a fresh clock.

    Paul

    Mathematicians are like Frenchmen: whenever you say something to them, they translate it into their own language, and at once it is something entirely different. (Goethe)
    #CPLEXOptimizers
    #DecisionOptimization


  • 3.  Re: question about cplex.tilim parameter

    Posted 09/11/12 08:49 PM

    Originally posted by: LeandroCC


    It seems to me you have your solve() call embedded in a while(is optimal) or something like that.
    #CPLEXOptimizers
    #DecisionOptimization


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