solution type for LP and QP

Specifies type of solution (basic or non basic) that CPLEX produces for a linear program (LP) or quadratic program (QP).

Purpose

Solution type for LP or QP

API	Parameter Name
C	CPXPARAM_SolutionType
C++	IloCplex::Param::SolutionType
Java	IloCplex.Param.SolutionType
.NET	Cplex.Param.SolutionType
OPL	solutiontype
Python	parameters.solutiontype
Interactive	solutiontype
Identifier	1147

Description

Specifies the type of solution (basic or non basic) that CPLEX attempts to compute for a linear program (LP) or for a quadratic program (QP). In this context, basic means having to do with the basis. When CPLEX offers a non basic solution, the solution consists of a pair of primal-dual solution vectors.

By default (that is, when the value of this parameter is 0 (zero) automatic), CPLEX seeks a basic solution (that is, a solution with a basis) for all linear programs (LP) and for all quadratic programs (QP).

When the value of this parameter is 1 (one), CPLEX seeks a basic solution, that is, a solution that includes a basis with a basic status for variables and constraints. In other words, CPLEX behaves the same way for the values 0 (zero) and 1 (one) of this parameter.

When the value of this parameter is 2, CPLEX seeks a pair of primal-dual solution vectors. This setting does not prevent CPLEX from producing status information, but in seeking a pair of primal-dual solution vectors, CPLEX possibly may not produce basic status information; that is, it is possible that CPLEX does not produce status information about which variables and constraints participate in the basis at this setting.

Table 1. Values
Value	Symbol	Meaning
0	`CPX_AUTO_SOLN`	Automatic: let CPLEX decide; default
1	`CPX_BASIC_SOLN`	CPLEX computes a basic solution.
2	`CPX_NONBASIC_SOLN`	CPLEX computes a primal-dual pair of solution-vectors