1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 2 /* */ 3 /* This file is part of the program and library */ 4 /* SCIP --- Solving Constraint Integer Programs */ 5 /* */ 6 /* Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB) */ 7 /* */ 8 /* Licensed under the Apache License, Version 2.0 (the "License"); */ 9 /* you may not use this file except in compliance with the License. */ 10 /* You may obtain a copy of the License at */ 11 /* */ 12 /* http://www.apache.org/licenses/LICENSE-2.0 */ 13 /* */ 14 /* Unless required by applicable law or agreed to in writing, software */ 15 /* distributed under the License is distributed on an "AS IS" BASIS, */ 16 /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ 17 /* See the License for the specific language governing permissions and */ 18 /* limitations under the License. */ 19 /* */ 20 /* You should have received a copy of the Apache-2.0 license */ 21 /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ 22 /* */ 23 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ 24 25 /**@file type_lpi.h 26 * @brief type definitions for specific LP solvers interface 27 * @author Tobias Achterberg 28 */ 29 30 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ 31 32 #ifndef __SCIP_TYPE_LPI_H__ 33 #define __SCIP_TYPE_LPI_H__ 34 35 #ifdef __cplusplus 36 extern "C" { 37 #endif 38 39 /** objective sense */ 40 enum SCIP_ObjSen 41 { 42 SCIP_OBJSEN_MAXIMIZE = -1, /**< maximize objective function */ 43 SCIP_OBJSEN_MINIMIZE = +1 /**< minimize objective function */ 44 }; 45 typedef enum SCIP_ObjSen SCIP_OBJSEN; 46 47 /** LP solver parameters */ 48 enum SCIP_LPParam 49 { 50 SCIP_LPPAR_FROMSCRATCH = 0, /**< solver should start from scratch at next call? */ 51 SCIP_LPPAR_FASTMIP = 1, /**< fast mip setting of LP solver */ 52 SCIP_LPPAR_SCALING = 2, /**< should LP solver use scaling? */ 53 SCIP_LPPAR_PRESOLVING = 3, /**< should LP solver use presolving? */ 54 SCIP_LPPAR_PRICING = 4, /**< pricing strategy */ 55 SCIP_LPPAR_LPINFO = 5, /**< should LP solver output information to the screen? */ 56 SCIP_LPPAR_FEASTOL = 6, /**< feasibility tolerance for primal variables and slacks, strictly positive */ 57 SCIP_LPPAR_DUALFEASTOL = 7, /**< feasibility tolerance for dual variables and reduced costs, strictly positive */ 58 SCIP_LPPAR_BARRIERCONVTOL = 8, /**< convergence tolerance used in barrier algorithm */ 59 SCIP_LPPAR_OBJLIM = 9, /**< objective limit (stop if objective is known be larger/smaller than limit for min/max-imization) */ 60 SCIP_LPPAR_LPITLIM = 10, /**< LP iteration limit, greater than or equal 0 */ 61 SCIP_LPPAR_LPTILIM = 11, /**< LP time limit, positive */ 62 SCIP_LPPAR_MARKOWITZ = 12, /**< Markowitz tolerance */ 63 SCIP_LPPAR_ROWREPSWITCH = 13, /**< simplex algorithm shall use row representation of the basis 64 * if number of rows divided by number of columns exceeds this value 65 * (0 <= value or -1 = valu ; if negative, this change never occurs) */ 66 SCIP_LPPAR_THREADS = 14, /**< number of threads used to solve the LP */ 67 SCIP_LPPAR_CONDITIONLIMIT = 15, /**< maximum condition number of LP basis counted as stable */ 68 SCIP_LPPAR_TIMING = 16, /**< type of timer (1 - cpu, 2 - wallclock, 0 - off) */ 69 SCIP_LPPAR_RANDOMSEED = 17, /**< inital random seed, e.g. for perturbations in the simplex (0: LP default) */ 70 SCIP_LPPAR_POLISHING = 18, /**< set solution polishing (0 - disable, 1 - enable) */ 71 SCIP_LPPAR_REFACTOR = 19 /**< set refactorization interval (0 - automatic) */ 72 }; 73 typedef enum SCIP_LPParam SCIP_LPPARAM; 74 75 /** LP pricing strategy */ 76 enum SCIP_Pricing 77 { 78 SCIP_PRICING_LPIDEFAULT = 0, /**< the SCIP/LP interface should use its preferred strategy */ 79 SCIP_PRICING_AUTO = 1, /**< the LP solver should use its preferred strategy */ 80 SCIP_PRICING_FULL = 2, /**< full pricing */ 81 SCIP_PRICING_PARTIAL = 3, /**< partial pricing */ 82 SCIP_PRICING_STEEP = 4, /**< steepest edge pricing */ 83 SCIP_PRICING_STEEPQSTART = 5, /**< steepest edge pricing without initial dual norms */ 84 SCIP_PRICING_DEVEX = 6 /**< devex pricing */ 85 }; 86 typedef enum SCIP_Pricing SCIP_PRICING; 87 88 /** basis status for columns and rows */ 89 enum SCIP_BaseStat 90 { 91 SCIP_BASESTAT_LOWER = 0, /**< (slack) variable is at its lower bound */ 92 SCIP_BASESTAT_BASIC = 1, /**< (slack) variable is basic */ 93 SCIP_BASESTAT_UPPER = 2, /**< (slack) variable is at its upper bound */ 94 SCIP_BASESTAT_ZERO = 3 /**< free variable is non-basic and set to zero */ 95 }; 96 typedef enum SCIP_BaseStat SCIP_BASESTAT; 97 98 /** LP solution quality quantities */ 99 enum SCIP_LPSolQuality 100 { 101 SCIP_LPSOLQUALITY_ESTIMCONDITION = 0, /**< estimated condition number of (scaled) basis matrix (SCIP_Real) */ 102 SCIP_LPSOLQUALITY_EXACTCONDITION = 1 /**< exact condition number of (scaled) basis matrix (SCIP_Real) */ 103 }; 104 typedef enum SCIP_LPSolQuality SCIP_LPSOLQUALITY; 105 106 typedef struct SCIP_LPi SCIP_LPI; /**< solver dependent LP interface */ 107 typedef struct SCIP_LPiState SCIP_LPISTATE; /**< complete LP state (i.e. basis information) */ 108 typedef struct SCIP_LPiNorms SCIP_LPINORMS; /**< LP pricing norms information */ 109 110 #ifdef __cplusplus 111 } 112 #endif 113 114 #endif 115