The OPTLP Procedure
- Overview
- Getting Started
-
Syntax
-
Details
Data Input and Output Presolve Pricing Strategies for the Primal and Dual Simplex Solvers Warm Start for the Primal and Dual Simplex Solvers The Network Simplex Algorithm The Interior Point Algorithm Iteration Log for the Primal and Dual Simplex Solvers Iteration Log for the Network Simplex Solver Iteration Log for the Interior Point Solver ODS Tables Irreducible Infeasible Set Memory Limit PROC OPTLP Macro Variable
-
Examples
- References
| Iteration Log for the Network Simplex Solver |
After finding the embedded network and formulating the appropriate relaxation, the network simplex solver uses a primal network simplex algorithm. In the case of a connected network, with one (weakly connected) component, the log shows the progress of the simplex algorithm. The following information is displayed in the iteration log:
- Iteration
indicates the iteration number.
- PrimalObj
indicates the primal objective value of the current solution.
- Primal Infeas
indicates the maximum primal infeasibility of the current solution.
- Time
indicates the time spent on the current component by network simplex.
The frequency of the simplex iteration log is controlled by the PRINTFREQ= option. The default value of the PRINTFREQ= option is 10,000.
If the network relaxation is disconnected, the information in the iteration log shows progress at the component level. The following information is displayed in the iteration log:
- Component
indicates the component number being processed.
- Nodes
indicates the number of nodes in this component.
- Arcs
indicates the number of arcs in this component.
- Iterations
indicates the number of simplex iterations needed to solve this component.
- Time
indicates the time spent so far in network simplex.
The frequency of the component iteration log is controlled by the PRINTFREQ= option. In this case, the default value of the PRINTFREQ= option is determined by the size of the network.
The PRINTLEVEL2= option adjusts the amount of detail shown. By default, PRINTLEVEL2= is set to MODERATE and reports as described previously. If set to NONE, no information is shown. If set to BASIC, the only information shown is a summary of the network relaxation and the time spent solving the relaxation. If set to AGGRESSIVE, in the case of one component, the log displays as described previously; in the case of multiple components, for each component, a separate simplex iteration log is displayed.