primal and dual reduction type
Specifies whether primal reductions, dual reductions, both, or neither are performed during preprocessing.
Purpose
Primal and dual reduction type
| API | Parameter Name | Name prior to V12.6.0 |
|---|---|---|
| C | CPXPARAM_Preprocessing_Reduce | CPX_PARAM_REDUCE |
| C++ | IloCplex::Param::Preprocessing::Reduce | Reduce (int) |
| OPL | reduce | |
| Interactive | preprocessing reduce | preprocessing reduce |
| Identifier | 1057 | 1057 |
Description
Specifies whether primal reductions, dual reductions, both, or neither are performed during preprocessing. These preprocessing reductions are also known as presolve reductions.
If your application uses lazy constraints (for example, you have explicitly added lazy constraints to the model before optimization, or you have registered lazy constraints from a callback by means of a method or routine, such as CPXsetlazyconstraintcallbackfunc) then CPLEX turns off dual reductions.
| Value | Symbol | Meaning |
|---|---|---|
| 0 | CPX_PREREDUCE_NOPRIMALORDUAL | No primal or dual reductions |
| 1 | CPX_PREREDUCE_PRIMALONLY | Only primal reductions |
| 2 | CPX_PREREDUCE_DUALONLY | Only dual reductions |
| 3 | CPX_PREREDUCE_PRIMALANDDUAL | Both primal and dual reductions; default |