[英]LP relaxation in CPLEX
当我在我的 model 下编写以下代码时,我可以获得一个宽松的值吗? 当我这样做时,我没有任何决策变量结果。 我需要改变什么吗?
main {
var status = 0;
thisOplModel.generate();
if (cplex.solve()) {
writeln("Integer Model");
writeln("OBJECTIVE: ",cplex.getObjValue());
if (cplex.getObjValue() != 1) {
status = -1;
}
}
thisOplModel.convertAllIntVars();
if (cplex.solve()) {
writeln("Relaxed Model");
writeln("OBJECTIVE: ",cplex.getObjValue());
if (cplex.getObjValue() != 0.5) {
status = -1;
}
}
(status);
}
当然。
int nbKids=300;
float costBus40=500;
float costBus30=400;
dvar int+ nbBus40;
dvar int+ nbBus30;
minimize
costBus40*nbBus40 +nbBus30*costBus30;
subject to
{
ctKids:40*nbBus40+nbBus30*30>=nbKids;
}
main {
var status = 0;
thisOplModel.generate();
if (cplex.solve()) {
writeln("Integer Model");
writeln("OBJECTIVE: ",cplex.getObjValue());
}
// relax integrity constraint
thisOplModel.convertAllIntVars();
if (cplex.solve()) {
writeln("Relaxed Model");
writeln("OBJECTIVE: ",cplex.getObjValue());
writeln("dual of the kids constraint = ",thisOplModel.ctKids.dual);
}
}
这使
Integer Model
OBJECTIVE: 3800
Relaxed Model
OBJECTIVE: 3750
dual of the kids constraint = 12.5
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.