linear reduction switch

Decides whether linear or full reductions occur during preprocessing.

Purpose

Linear reduction switch

API Parameter Name Name prior to V12.6.0
C CPXPARAM_Preprocessing_Linear CPX_PARAM_PRELINEAR
C++ IloCplex::Param::Preprocessing::Linear PreLinear (int)
OPL prelinear
Interactive preprocessing linear preprocessing linear
Identifier 1058 1058

Description

Decides whether linear or full reductions occur during preprocessing. If only linear reductions are performed, each variable in the original model can be expressed as a linear form of variables in the presolved model. This condition guarantees, for example, that users can add their own custom cuts to the presolved model.

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 nonlinear reductions.

Table 1. Values
Value Meaning
0 Perform only linear reductions
1 Perform full reductions; default