SOS1 reformulations

Defines whether special ordered sets of type 1 (SOS1) should be reformulated as linear constraints.

Purpose

SOS1 reformulations

API	Parameter Name
C	CPXPARAM_Preprocessing_SOS1Reform
C++	IloCplex::Param::Preprocessing::SOS1Reform
Java	IloCplex.Param.Preprocessing.SOS1Reform
.NET	Cplex.Param.Preprocessing.SOS1Reform
OPL	sos1reform
Python	parameters.preprocessing.sos1reform
Interactive	preprocessing sos1reform
Identifier	2230

Description

This parameter allows you to control the reformulation of special ordered sets of type 1 (SOS1), which can be applied during the solution process of problems containing these sets. Setting the value of this parameter to 0 (zero), the default, specifies that the SOS1 should be reformulated as linear constraints only if this is deemed to be helpful.

For a definition of special ordered sets, see Using special ordered sets (SOS). For a more thorough discussion on the reformulation of special ordered sets, see Automatic reformulation of special ordered sets.

Table 1. Values
Value	Meaning
-1	No reformulation: CPLEX does not reformulate special ordered sets of type 1 (SOS1) as linear constraints
0	Automatic: let CPLEX decide; default
1	Logarithmic: CPLEX reformulates special ordered sets of type 1 (SOS1) as linear constraints, with a reformulation which is logarithmic in the size of the special ordered sets