Scippy

SCIP

Solving Constraint Integer Programs

Functions
heur_rounding.h File Reference
Primal Heuristics

Detailed Description

LP rounding heuristic that tries to recover from intermediate infeasibilities.

Author
Tobias Achterberg

Rounding heuristic that starts from an LP-feasible point and reduces the number of fractional variables by one in each step. As long as no LP row is violated, the algorithm iterates over the fractional variables and applies a rounding into the direction of fewer locks, updating the activities of the LP rows after each step. If there is a violated LP row, the heuristic will try to find a fractional variable that can be rounded in a direction such that the violation of the constraint is decreased, using the number of up- and down-locks as a tie breaker. If no rounding can decrease the violation of the constraint, the procedure is aborted.

Definition in file heur_rounding.h.

#include "scip/scip.h"

Go to the source code of this file.

Functions

SCIP_RETCODE SCIPincludeHeurRounding (SCIP *scip)
 

Function Documentation

SCIP_RETCODE SCIPincludeHeurRounding ( SCIP *  scip)

creates the rounding heuristic with infeasibility recovering and includes it in SCIP

Parameters
scipSCIP data structure

Definition at line 741 of file heur_rounding.c.

References DEFAULT_ONCEPERNODE, DEFAULT_SUCCESSFACTOR, HEUR_DESC, HEUR_DISPCHAR, HEUR_FREQ, HEUR_FREQOFS, HEUR_MAXDEPTH, HEUR_NAME, HEUR_PRIORITY, HEUR_TIMING, HEUR_USESSUBSCIP, NULL, SCIP_CALL, SCIP_OKAY, SCIPaddBoolParam(), SCIPaddIntParam(), SCIPallocMemory, SCIPincludeHeurBasic(), SCIPsetHeurCopy(), SCIPsetHeurExit(), SCIPsetHeurExitsol(), SCIPsetHeurFree(), SCIPsetHeurInit(), SCIPsetHeurInitsol(), and TRUE.

Referenced by SCIPincludeDefaultPlugins().