# SCIP

Solving Constraint Integer Programs

 heur_actconsdiving.h Go to the documentation of this file. 1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the program and library */ 4 /* SCIP --- Solving Constraint Integer Programs */ 5 /* */ 6 /* Copyright (C) 2002-2015 Konrad-Zuse-Zentrum */ 7 /* fuer Informationstechnik Berlin */ 8 /* */ 9 /* SCIP is distributed under the terms of the ZIB Academic License. */ 10 /* */ 11 /* You should have received a copy of the ZIB Academic License */ 12 /* along with SCIP; see the file COPYING. If not email to scip@zib.de. */ 13 /* */ 14 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 15  16 /**@file heur_actconsdiving.h 17  * @ingroup PRIMALHEURISTICS 18  * @brief LP diving heuristic that chooses fixings w.r.t. the active constraints the variable appear in 19  * @author Tobias Achterberg 20  * 21  * Diving heuristic: Iteratively fixes some fractional variable and resolves the LP-relaxation, thereby simulating a 22  * depth-first-search in the tree. Active Constraint Diving chooses a variable based on the active LP rows (equations 23  * are counted twice here). The variable score is calculated as a convex combination of the number of constraints the 24  * variable appears in, the sum of all positive coefficients and the absolute sum of all negative coefficients. The 25  * chosen variable is then rounded to the closest integer. One-level backtracking is applied: If the LP gets infeasible, 26  * the last fixings is undone, and the opposite fixing is tried. If this is infeasible, too, the procedure aborts. 27  */ 28  29 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 30  31 #ifndef __SCIP_HEUR_ACTCONSDIVING_H__ 32 #define __SCIP_HEUR_ACTCONSDIVING_H__ 33  34  35 #include "scip/scip.h" 36  37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40  41 /** creates the actconsdiving heuristic and includes it in SCIP */ 42 extern 44  SCIP* scip /**< SCIP data structure */ 45  ); 46  47 #ifdef __cplusplus 48 } 49 #endif 50  51 #endif SCIPincludeHeurActconsdivingSCIP_RETCODE SCIPincludeHeurActconsdiving(SCIP *scip) SCIP_RETCODEenum SCIP_Retcode SCIP_RETCODEDefinition: type_retcode.h:53 SCIPstruct Scip SCIPDefinition: type_scip.h:30 scip.hSCIP callable library. Generated on Wed Jul 22 2015 for SCIP Doxygen Documentation by doxygen (1.8.6) © 2024 by Zuse Institute Berlin (ZIB), Imprint designed with Bootstrap