calculate QCP dual values
Instructs CPLEX to calculate the dual values of a quadratically constrained problem
Purpose
calculating QCP dual values
| API | Parameter Name | Name prior to V12.6.0 |
|---|---|---|
| C | CPXPARAM_Preprocessing_QCPDuals | CPX_PARAM_CALCQCPDUALS |
| C++ | IloCplex::Param::Preprocessing::QCPDuals | CalcQCPDuals (int) |
| OPL | not available | |
| Interactive | preprocessing qcpduals | preprocessing qcpduals |
| Identifier | 4003 | 4003 |
Description
This parameter determines whether CPLEX preprocesses a quadratically constrained program (QCP) so that the user can access dual values for the QCP.
If this parameter is set to 0 (zero), then CPLEX does not calculate dual values for the QCP.
If this parameter is set to 1 (one), its default value, then CPLEX calculates dual values for the QCP as long as the calculations do not interfere with presolve reductions.
If this parameter is set to 2, then CPLEX calculates dual values and moreover, CPLEX disables any presolve reductions that interfere with these dual-value calculations.
For more information about accessing dual values of a QCP, see the topic Accessing dual values and reduced costs of QCP solutions in the CPLEX User's Manual.
For more information about presolve reductions, see the topic Advanced presolve routines in the CPLEX User's Manual.
Values
| Value | Meaning | Symbol in Callable Library (C API) | Symbol in C++, Java, .NET APIs | Symbol in Python API |
|---|---|---|---|---|
| 0 | Do not calculate dual values for the QCP | CPX_QCPDUALS_NO | QCPDualsNo | no |
| 1 | Calculate dual values for the QCP as long as the calculations do not interfere with presolve reductions. default | CPX_QCPDUALS_IFPOSSIBLE | QCPDualsIfPossible | if_possible |
| 2 | Calculate dual values and disable any presolve reductions that interfere with these calculations. | CPX_QCPDUALS_FORCE | QCPDualsForce | force |