Topic
  • 3 replies
  • Latest Post - ‏2013-11-25T16:39:34Z by ChrisBr
CP-Man
CP-Man
8 Posts

Pinned topic Stuck in search!

‏2013-11-12T15:07:37Z |

Hi everyone,

I'm trying to implement LDS in Shaw (1998) for my routing problem. I developed the algorithm form my own problem, and debugged it many times. It seems to be correct, however, it returns "No feasible solution found" all the time. I'm sure my variable and value selection algorithms are not the problem since I debugged them as well, and also replacing them with other things like: IlcInt var = IlcChooseMinSizeInt(x);   IlcInt val = x[var].getMin(); returns the same result!

 

I've been thinking about every little thing for very long, however, came up with nothing. Would you please let me know how I could resolve this, or if you've had such an experience using ILOGOAL?

 

Thanks!

Updated on 2013-11-12T15:08:19Z at 2013-11-12T15:08:19Z by CP-Man
  • ChrisBr
    ChrisBr
    60 Posts

    Re: Stuck in search!

    ‏2013-11-12T17:52:32Z  

    Hello,

    You might have a look to User's Manual
    http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r5/index.jsp
    CP Optimizer > CP Optimizer Extensions User²s Manual > Writing goals > Writing your own goal
    and especially at:
    CP Optimizer > CP Optimizer Extensions User²s Manual > Writing goals > Writing your own goal > Using ILOCPGOALWRAPPER to wrap the goals

    You may have a look also at this thread which seems to be related to your concern:
    https://www.ibm.com/developerworks/community/forums/html/topic?id=48088bcc-2a46-45a8-b3d9-c3edf63e418e&ps=25

    Nevertheless, if you still need some help, you might have to give us more information (how is your goal written for example).

    I hope this helps,

    Chris.
     

  • CP-Man
    CP-Man
    8 Posts

    Re: Stuck in search!

    ‏2013-11-25T14:39:49Z  
    • ChrisBr
    • ‏2013-11-12T17:52:32Z

    Hello,

    You might have a look to User's Manual
    http://pic.dhe.ibm.com/infocenter/cosinfoc/v12r5/index.jsp
    CP Optimizer > CP Optimizer Extensions User²s Manual > Writing goals > Writing your own goal
    and especially at:
    CP Optimizer > CP Optimizer Extensions User²s Manual > Writing goals > Writing your own goal > Using ILOCPGOALWRAPPER to wrap the goals

    You may have a look also at this thread which seems to be related to your concern:
    https://www.ibm.com/developerworks/community/forums/html/topic?id=48088bcc-2a46-45a8-b3d9-c3edf63e418e&ps=25

    Nevertheless, if you still need some help, you might have to give us more information (how is your goal written for example).

    I hope this helps,

    Chris.
     

    Thanks Chris for the reply.

     

    I tried the algorithm from the link above, exactly as it is (everything is the same, the search, value and variable selections, etc). I merely customized it to my problem. However, it keeps returning me the same result! I wonder if it's due to an inconsistency or something?

     

    Thanks!

  • ChrisBr
    ChrisBr
    60 Posts

    Re: Stuck in search!

    ‏2013-11-25T16:39:34Z  
    • CP-Man
    • ‏2013-11-25T14:39:49Z

    Thanks Chris for the reply.

     

    I tried the algorithm from the link above, exactly as it is (everything is the same, the search, value and variable selections, etc). I merely customized it to my problem. However, it keeps returning me the same result! I wonder if it's due to an inconsistency or something?

     

    Thanks!

    Hello Hossein,

    Yes, the fact that the engine doesn't find any solution can come from an inconsistency (or from a limit reached).
    I suggest to try the Conflict Refiner.
           CP Optimizer > CP Optimizer C++ API Reference Manual > Concepts > Conflict Refiner in CP Optimizer
    If this doesn't help, please send us your model.

    Regards,

    Chris.