[Scip] Constraints which involve two variables

[Martina Astegno]

Hi all!

I'm modelling a clustering problem and it requires to use a binary variable for each element and for each cluster.
w[i][j] = 1 if element i is in cluster j; 0 otherwise.

I have to define another binary variable, z[i][l][j][h], that is equal to 1 if (w[i][j] and w[l][h]) = 1; 0 otherwise. 

AND logic operator is implemented introducing 3 new constraints in the problem:
z[i][l][j][h] <= w[i][j]
z[i][l][j][h] <= w[l][h]
z[i][l][j][h] >= w[i][j] + w[l][h] -1

So, when I have to create the solver, to define the constraint on z variable, in function SCIPcreateConsLinear(), I don't know how to fix the lb/ub equal to the value of the w variable, because it's  SCIP_VAR* type.
 It's possible to know the value associated to a variable with the function SCIPgetSolVal() only after solve method and not during the solver  construction.

Any idea what's going on?

              
Thanks!

Marty



      
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