relative gap for solution pool
Sets a relative tolerance on the objective value for the solutions in the solution pool.
Purpose
Relative gap for the solution pool
| API | Parameter Name | Name prior to V12.6.0 |
|---|---|---|
| C | CPXPARAM_MIP_Pool_RelGap | CPX_PARAM_SOLNPOOLGAP |
| C++ | IloCplex::Param::MIP::Pool::RelGap | SolnPoolGap (double) |
| OPL | solnpoolgap | |
| Interactive | mip pool relgap | mip pool relgap |
| Identifier | 2105 | 2105 |
Description
Sets a relative tolerance on the objective value for the solutions in the solution pool. Solutions that are worse (either greater in the case of a minimization, or less in the case of a maximization) than the incumbent solution by this measure are not kept in the solution pool. For example, if you set this parameter to 0.01, then solutions worse than the incumbent by 1% or more will be discarded.
Values of the absolute gap for solution pool (SolnPoolAGap or CPX_PARAM_SOLNPOOLAGAP) and the relative gap for solution pool (SolnPoolGap or CPX_PARAM_SOLNPOOLGAP) may differ: For example, you may specify that solutions must be within 15 units by means of the solution pool absolute gap and within 1% of the incumbent by means of the solution pool relative gap. A solution is accepted in the pool only if it is valid for both the relative and the absolute gaps.
The solution pool relative gap parameter can also be used as a stopping criterion for the populate procedure: if populate cannot enumerate any more solutions that satisfy this objective quality, then it will stop. In the presence of both an absolute and a relative solution pool gap parameter, populate will stop when the smaller of the two is reached.
Values
Any nonnegative real number; default: 1.0e+75.