Originally posted by: SystemAdmin

[agus said:]

Hi,

Is there a way to find the cardinality of certain members of a set?

Here is my code:

tuple flight {
key string flightID;
  {int} nodes;
  {int} holdingNodes;
  int destination;
  int origin;
  string status;
  string class;
  int OBT;
  int ETA;
}

{flight} Flights = {
<", {6,1,2,3}, {3}, 3,6, "dept", "s", 1,0>,
<", {6,7,2,3}, {3}, 3,6, "dept", "h", 1,0>,
<", {35, 34, 33, 32, 31}, {35}, 31, 35, "arri", "h", 0, 700>,
<", {35, 34, 33, 32, 31,26}, {35}, 26, 35, "arri", "s", 0, 800>
};


I would like to find the number of: i.status == "dept" in set the "Flights"

I tried:

subject to {

//Fairness 2
forall (i in Flights: i.status == "dept")
t[i][i.origin] - i.OBT <= (sum (i in Flights: i.status == "dept") (t[i][i.origin] - i.OBT)) / card (Flights: i.status =="dept");<br />
}


But it didn't work.
Like you can see I am trying to find an average value, but for that I need to find the cardinality first.

Could anyone help me with this?

Thanks,

agus
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

[UDOPS said:]

Here are things I tried. I don't know if they will paste into constraints, but I think you get the idea.


tuple flight {
key string flightID;
  {int} nodes;
  {int} holdingNodes;
  int destination;
  int origin;
  string status;
  string class;
  int OBT;
  int ETA;
}

{flight} Flights = {
<", {6,1,2,3}, {3}, 3,6, "dept", "s", 1,0>,
<", {6,7,2,3}, {3}, 3,6, "dept", "h", 1,0>,
<", {35, 34, 33, 32, 31}, {, 31, 35, "arri", "h", 0, 700>,
<", {35, 34, 33, 32, 31,26}, {35}, 26, 35, "arri", "s", 0, 800>
};

{flight} Flightdept = {f | f in Flights: f.status=="dept"};
int Deptcount = card(Flightdept);
int Deptcountalt = card({f | f in Flights: f.status=="dept"}); //alternate form

//more ideas

tuple shortlist {
key string flightID;
int destination;
}

{35}shortlist} Deptlist = {<f.flightID, f.destination> | f in Flights: f.status=="dept"};


execute{
for (var f in Flightdept) {
writeln(f.flightID+", "+f.status)
}
writeln(Deptcount)
writeln(Deptcountalt)
writeln(Deptlist)
}
#DecisionOptimization
#OPLusingCPLEXOptimizer