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11 replies Latest Post - ‏2012-12-30T21:57:22Z by SystemAdmin
SystemAdmin
SystemAdmin
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Pinned topic expansion of a constraint

‏2012-11-07T11:58:45Z |
Hello all. i wanna see full expansion of a constraint in cplex OPL. is it possible. let me explain what i want with an example.

in the screen shot there is a frame which writes "select a constrain to show its expansion". i select one of the constrain but i'm not able to see it's expansion. for example in the first constraint i want to see "x121+x131+x141+x151<=1" instead of sum(j in 1..5: j != 1) x[1](j)[1] <= 1 . thanks...
Updated on 2012-12-30T21:57:22Z at 2012-12-30T21:57:22Z by SystemAdmin
  • arguen
    arguen
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    Re: expansion of a constraint

    ‏2012-11-08T07:07:42Z  in response to SystemAdmin
    Hi,
    You should see it from "Problem Browser" once the engine found a solution.
    I attached my problem browser screenshot and the constraints to give you an example what should you expect. (#s are employed as separators between indices)

    From "Window" tab at the top --> Show view -- > Problem Browser. Scroll down and you will see your constraints.

    Hope that this helps.
  • arguen
    arguen
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    Re: expansion of a constraint

    ‏2012-11-08T07:09:23Z  in response to SystemAdmin
    oops. I forgot the attachment in the last post.
    • SystemAdmin
      SystemAdmin
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      Re: expansion of a constraint

      ‏2012-11-08T20:24:54Z  in response to arguen
      first of all thanks.

      but i am not able to see what i wanna see. i am sending you print screen my problem browser. for example in constraint 1 instead of "sum(i in 1..7: i != 1) x[1](i)[1] <=1" i wanna see "x111+x121+x131+x141+x151+x161+x171<=1" . can you tell me how can i do that.
      • SystemAdmin
        SystemAdmin
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        Re: expansion of a constraint

        ‏2012-12-14T20:49:58Z  in response to SystemAdmin
        Have you tried mouse-overing the constraint in the Problem Browser tab and clicking on the arrow-plus icon labeled "Show data view..."? It should open a new window in the center panel with the constraint expansion. Image attached, there's a red square highlighting the icon I said.

        Regards,
        Stefano
        • SystemAdmin
          SystemAdmin
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          Re: expansion of a constraint

          ‏2012-12-15T20:32:05Z  in response to SystemAdmin
          Thanks for your attention. i have already tried what you said but this is not what i want.the example you send in the image constraints are in closed form: sum(j in 0..1, k in 0..1)a[j][k]<=1

          but what i want is something like this: a[0][0]+a[0][1]+a[1][0]+a[1][1]<=1
          • SystemAdmin
            SystemAdmin
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            Re: expansion of a constraint

            ‏2012-12-16T12:17:47Z  in response to SystemAdmin
            Probably I forgot to mention that you should also select the constraint from the list and its expansion will appear in the "Constraint detail" panel. Image attached.

            Regards,
            Stefano
            • SystemAdmin
              SystemAdmin
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              Re: expansion of a constraint

              ‏2012-12-16T14:44:26Z  in response to SystemAdmin
              ok this is what i want :) but i am not able to see anything in constraint detail section. there is "select a constraint to show its expansion". then i select one of the constraint but still there is nothing. is there a option or somethin like which i might turn on to see the constraint detail? i'll send you the screen shot...
            • SystemAdmin
              SystemAdmin
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              Re: expansion of a constraint

              ‏2012-12-16T14:53:49Z  in response to SystemAdmin
              this screen shot belongs to gas production example(gas.mod) in ilog examples.
              • SystemAdmin
                SystemAdmin
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                Re: expansion of a constraint

                ‏2012-12-16T15:45:30Z  in response to SystemAdmin
                I tried myself with that model, and indeed it seems to kind-of-work, even if the expanded sum of the variables is directly replaced by the final sum of the actual values of variables, making the feature a bit useless (image attached). I tried this model with CPLEX Studio IDE 12.5, but by looking at your screenshot it looks like that you're using some old version of CPLEX Studio IDE (there is that yellow "Academic" tag on top right). It could be some bug, as I don't remember having to set any option to enable the constraint detail function. However, I'd wait for someone from IBM to confirm it.

                Regards,
                Stefano
                • SystemAdmin
                  SystemAdmin
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                  Re: expansion of a constraint

                  ‏2012-12-16T16:06:33Z  in response to SystemAdmin
                  sir really thanks for your attention. i have another release 12.4 and i tried it than it works :) this must be a bug as you said. if you have further information please contact me :) thanks again...
                • SystemAdmin
                  SystemAdmin
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                  Re: expansion of a constraint

                  ‏2012-12-30T21:57:22Z  in response to SystemAdmin
                  We can see expansions of consraints in constraint detail section but for very long constraints we are not able to see hole constraint....do u know how to see hole constraint expansion?