limit on the number of presolve passes made

Limits the number of presolve passes that CPLEX makes during preprocessing.

Purpose

Limit on the number of presolve passes during preprocessing

API	Parameter Name	Name prior to V12.6.0
C	CPXPARAM_Preprocessing_NumPass	CPX_PARAM_PREPASS
C++	IloCplex::Param::Preprocessing::NumPass	PrePass (int)
Java	IloCplex.Param.Preprocessing.NumPass	PrePass (int)
.NET	Cplex.Param.Preprocessing.NumPass	PrePass (int)
OPL	prepass	prepass
Python	parameters.preprocessing.numpass	preprocessing.numpass
Interactive	preprocessing numpass	preprocessing numpass
Identifier	1052	1052

Description

Limits the number of presolve passes that CPLEX makes during preprocessing.

When this parameter is set to a positive value, presolve is applied the specified number of times, or until no more reductions are possible.

At the default value of -1, presolve continues only if it seems to be helping.

When this parameter is set to zero, CPLEX does not enter its main presolve loop, but other reductions may occur, depending on settings of other parameters and characteristics of your model. In other words, setting this parameter to 0 (zero) is not equivalent to turning off the presolve switch (CPX_PARAM_PREIND, PreInd). To turn off presolve, use the presolve switch (CPX_PARAM_PREIND, PreInd) instead.

Table 1. Values
Value	Meaning
-1	Automatic: let CPLEX choose; presolve continues as long as helpful; default
0	Do not use presolve; other reductions may still occur
Any positive integer	Apply presolve specified number of times