Decision Optimization

Originally posted by: RobertH79

Hi there!

 

 

I have got a set of datetimes as follows:

start = [ 27.00 35.00 59.00 36.00 30.00 36.00 43.00 67.00 ];

finish = [ 30.00 38.00 62.00 44.00 34.00 40.00 47.00 71.00 ];

These numbers represent three days planning period in hours.

These values index some events.

float start[i in Events] = ...;

float finish[i in Events] = ...;

I have a dvar int t_finish[i in Events];

I have a user defined variable to set the desired finishing time for every day during the planning period.  Its given in a 24 hours format. Finally I would like to get the values that are below the user defined limit.

So I think I should use integer division all the values on the above values:

forall (i in Events) t_finish[i] - (t_finish[i] div 24)*24 <= UserValue;

forall (i in Events) t_finish[i] - (t_finish[i] div 24)*24 >= 0;

But I have got the next errors :

CPLEX(default) cannot extract expression: forall (i in Events)  0  <= t_finish[i] + (t_finish[i] div 24)*(-24);

CPLEX(default) cannot extract expression: t_finish[i] div 24.

CPLEX(default) cannot extract model: IloAlgorithm cannot extract extractable.

 

I think its because of the decision variable and the div.

Does anybody can advise a solution to the definition.

 

Thank you in advance.

Robert

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

using CP Optimizer could be a way:

.mod

using CP;
 range Events=1..8;
 int UserValue=1;
 
  float start[i in Events] = ...;

float finish[i in Events] = ...;

dvar int t_finish[i in Events];

subject to
{

forall (i in Events) t_finish[i] - (t_finish[i] div 24)*24 <= UserValue;

forall (i in Events) t_finish[i] - (t_finish[i] div 24)*24 >= 0;
}

and .dat

start = [ 27.00 35.00 59.00 36.00 30.00 36.00 43.00 67.00 ];

finish = [ 30.00 38.00 62.00 44.00 34.00 40.00 47.00 71.00 ];

regards

 

Alex Fleischer

#DecisionOptimization
#OPLusingCPLEXOptimizer