Originally posted by: SystemAdmin

[ArushGadkar said:]

Hello all,
I have the following problem and would appreciate any suggestions on it.

I have a a variable matrix A[5][2] declared as an IloNumVarArray and a variable vector say U[5]. What i want to do is this:

Lets say for example A= [1  0]
                                [1  0]
                                [0  1]
                                [0  1]
                                [1  0]

then for every column of A I want to perform the following procedure:
add the index to a vector S (C++) if the value is 1. i.e in the first step it will take the first column of A and add to S the numbers 1,2,5 (since it is 1 at that position) 
The procedure( some function) will add constraints to the model (for example in the form U1 + U2 <=100, U5 <30... so on)<br />
then it takes the second column and i want to add 3, 4 to S and repeat the procedure.

I am having difficulties adding these indices to S.
I tried the following pseudocode

for(all j = 1 to 2)
{
  for(all i= 1 to 5)
  {if(A[i][j] = = 1)
  S.push_back(i)
  }
call procedure to add constraints.
}

this wont work as it says cannot use if to IloNumVar.

Could you help me out with this problem. your help is greatly appreciated.

Thanks
Arush



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#DecisionOptimization

Originally posted by: SystemAdmin

[akshayg said:]

Shouldnt it be if(A[i][j] == 1)

That could be the source of your error.
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#DecisionOptimization

Originally posted by: SystemAdmin

[ArushGadkar said:]

Hello,
Actually i did implement A[i][j]. It was a typo here. Sorry about that.
I was wondering if u have a Variable array declared as IloNumVarArray can u access it's elements by using the if condition.
e.g if(Y[j] == 1) where Y is declared as IloNumVarArray.

Thanks
Arush.
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#DecisionOptimization

Originally posted by: SystemAdmin

[notdarkyet said:]

I do not quite understand: If A is a IloNumVarAray, its elements are VARIABLES and not fixed values - so of course you can't use their values in the decision about formulating constraints.
If your matrix is fixed, you should use IloNumArray instead. This should be possible to be used i a way you intend.
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#DecisionOptimization

Originally posted by: SystemAdmin

[notdarkyet said:]

Or was just the subject wrong and you wanted to evaluate a solution and not formulate problem constraints?
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