Decision Optimization

Hello moderators & IBM community:

I am working on a scheduling formulation in OPL and using CP Optimizer as a solver engine.

In this context, I have the following interval variable:

dvar interval itvs[t in Tasks] size t.pt;

I want to suggest a starting solution for the interval variable itvs to CP Optimizer.

For instance, I would like to set a "starting point" for each start time of itvs[t] that generates a feasible solution for the problem being solved.

Could you please provide a small example of how can this be achieved? 

Hi,

I shared an example at https://stackoverflow.com/questions/63911236/how-to-give-to-cp-optimizer-an-initial-feasible-solution

using CP;range r = 1..10;dvar interval x[r] size 1;dvar interval y[r] size 1;// The following array of values (defined as data) will be used as  // a starting solution to warm-start the CP Optimizer search.int values[i in r] = (i==5)? 10 : 0;     minimize sum( i in r ) startOf(x[i]) + sum( j in r ) startOf(y[j]);subject to{ctSum: sum( i in r ) startOf(x[i]) >= 10;forall( j in r ) ctEqual: startOf(y[j]) == j;}   execute{for(i in r) write(Opl.startOf(x[i])," ");writeln();}main{thisOplModel.generate();var sol=new IloOplCPSolution();for(var i=1;i<=10;i++) sol.setStart(thisOplModel.x[i],thisOplModel.values[i]);cp.solve();thisOplModel.postProcess();cp.setStartingPoint(sol);cp.solve();thisOplModel.postProcess();}

Hello moderators & IBM community:

I am working on a scheduling formulation in OPL and using CP Optimizer as a solver engine.

In this context, I have the following interval variable:

dvar interval itvs[t in Tasks] size t.pt;

I want to suggest a starting solution for the interval variable itvs to CP Optimizer.

For instance, I would like to set a "starting point" for each start time of itvs[t] that generates a feasible solution for the problem being solved.

Could you please provide a small example of how can this be achieved? 

Thank you Alex for your answer.

I was wondering if there exists an easy way to do the same. I would like to provide the starting solution to CP Optimizer in the following manner:  

Hi,

I shared an example at https://stackoverflow.com/questions/63911236/how-to-give-to-cp-optimizer-an-initial-feasible-solution

using CP;range r = 1..10;dvar interval x[r] size 1;dvar interval y[r] size 1;// The following array of values (defined as data) will be used as  // a starting solution to warm-start the CP Optimizer search.int values[i in r] = (i==5)? 10 : 0;     minimize sum( i in r ) startOf(x[i]) + sum( j in r ) startOf(y[j]);subject to{ctSum: sum( i in r ) startOf(x[i]) >= 10;forall( j in r ) ctEqual: startOf(y[j]) == j;}   execute{for(i in r) write(Opl.startOf(x[i])," ");writeln();}main{thisOplModel.generate();var sol=new IloOplCPSolution();for(var i=1;i<=10;i++) sol.setStart(thisOplModel.x[i],thisOplModel.values[i]);cp.solve();thisOplModel.postProcess();cp.setStartingPoint(sol);cp.solve();thisOplModel.postProcess();}

Hello moderators & IBM community:

I am working on a scheduling formulation in OPL and using CP Optimizer as a solver engine.

In this context, I have the following interval variable:

dvar interval itvs[t in Tasks] size t.pt;

I want to suggest a starting solution for the interval variable itvs to CP Optimizer.

For instance, I would like to set a "starting point" for each start time of itvs[t] that generates a feasible solution for the problem being solved.

Could you please provide a small example of how can this be achieved?