Scippy

SCIP

Solving Constraint Integer Programs

cons_sos1.h
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3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
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24 
25 /**@file cons_sos1.h
26  * @ingroup CONSHDLRS
27  * @brief constraint handler for SOS type 1 constraints
28  * @author Tobias Fischer
29  * @author Marc Pfetsch
30  *
31  */
32 
33 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
34 
35 #ifndef __SCIP_CONS_SOS1_H__
36 #define __SCIP_CONS_SOS1_H__
37 
38 
39 #include "scip/def.h"
40 #include "scip/type_cons.h"
41 #include "scip/type_misc.h"
42 #include "scip/type_retcode.h"
43 #include "scip/type_scip.h"
44 #include "scip/type_sol.h"
45 #include "scip/type_var.h"
46 
47 #ifdef __cplusplus
48 extern "C" {
49 #endif
50 
51 /** creates the handler for SOS1 constraints and includes it in SCIP
52  *
53  * @ingroup ConshdlrIncludes
54  * */
55 SCIP_EXPORT
57  SCIP* scip /**< SCIP data structure */
58  );
59 
60 /**@addtogroup CONSHDLRS
61  *
62  * @{
63  *
64  * @name Specially Ordered Set (SOS) Type 1 Constraints
65  *
66  * @{
67  *
68  * A specially ordered set of type 1 (SOS1) is a sequence of variables such that at most one
69  * variable is nonzero. The special case of two variables arises, for instance, from equilibrium or
70  * complementary conditions like \f$x \cdot y = 0\f$. Note that it is in principle allowed that a
71  * variable appears twice, but it then can be fixed to 0.
72  */
73 
74 /** creates and captures an SOS1 constraint
75  *
76  * We set the constraint to not be modifable. If the weights are non
77  * NULL, the variables are ordered according to these weights (in
78  * ascending order).
79  *
80  * @note The constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons().
81  */
82 SCIP_EXPORT
84  SCIP* scip, /**< SCIP data structure */
85  SCIP_CONS** cons, /**< pointer to hold the created constraint */
86  const char* name, /**< name of constraint */
87  int nvars, /**< number of variables in the constraint */
88  SCIP_VAR** vars, /**< array with variables of constraint entries */
89  SCIP_Real* weights, /**< weights determining the variable order, or NULL if natural order should be used */
90  SCIP_Bool initial, /**< should the LP relaxation of constraint be in the initial LP?
91  * Usually set to TRUE. Set to FALSE for 'lazy constraints'. */
92  SCIP_Bool separate, /**< should the constraint be separated during LP processing?
93  * Usually set to TRUE. */
94  SCIP_Bool enforce, /**< should the constraint be enforced during node processing?
95  * TRUE for model constraints, FALSE for additional, redundant constraints. */
96  SCIP_Bool check, /**< should the constraint be checked for feasibility?
97  * TRUE for model constraints, FALSE for additional, redundant constraints. */
98  SCIP_Bool propagate, /**< should the constraint be propagated during node processing?
99  * Usually set to TRUE. */
100  SCIP_Bool local, /**< is constraint only valid locally?
101  * Usually set to FALSE. Has to be set to TRUE, e.g., for branching constraints. */
102  SCIP_Bool dynamic, /**< is constraint subject to aging?
103  * Usually set to FALSE. Set to TRUE for own cuts which
104  * are separated as constraints. */
105  SCIP_Bool removable, /**< should the relaxation be removed from the LP due to aging or cleanup?
106  * Usually set to FALSE. Set to TRUE for 'lazy constraints' and 'user cuts'. */
107  SCIP_Bool stickingatnode /**< should the constraint always be kept at the node where it was added, even
108  * if it may be moved to a more global node?
109  * Usually set to FALSE. Set to TRUE to for constraints that represent node data. */
110  );
111 
112 /** creates and captures an SOS1 constraint
113  * in its most basic variant, i. e., with all constraint flags set to their default values, which can be set
114  * afterwards using SCIPsetConsFLAGNAME() in scip.h
115  *
116  * @see SCIPcreateConsSOS1() for the default constraint flag configuration
117  *
118  * @warning Do NOT set the constraint to be modifiable manually, because this might lead
119  * to wrong results as the variable array will not be resorted
120  *
121  * @note the constraint gets captured, hence at one point you have to release it using the method SCIPreleaseCons()
122  */
123 SCIP_EXPORT
125  SCIP* scip, /**< SCIP data structure */
126  SCIP_CONS** cons, /**< pointer to hold the created constraint */
127  const char* name, /**< name of constraint */
128  int nvars, /**< number of variables in the constraint */
129  SCIP_VAR** vars, /**< array with variables of constraint entries */
130  SCIP_Real* weights /**< weights determining the variable order, or NULL if natural order should be used */
131  );
132 
133 /** adds variable to SOS1 constraint, the position is determined by the given weight */
134 SCIP_EXPORT
136  SCIP* scip, /**< SCIP data structure */
137  SCIP_CONS* cons, /**< constraint */
138  SCIP_VAR* var, /**< variable to add to the constraint */
139  SCIP_Real weight /**< weight determining position of variable */
140  );
141 
142 /** appends variable to SOS1 constraint */
143 SCIP_EXPORT
145  SCIP* scip, /**< SCIP data structure */
146  SCIP_CONS* cons, /**< constraint */
147  SCIP_VAR* var /**< variable to add to the constraint */
148  );
149 
150 /** gets number of variables in SOS1 constraint */
151 SCIP_EXPORT
152 int SCIPgetNVarsSOS1(
153  SCIP* scip, /**< SCIP data structure */
154  SCIP_CONS* cons /**< constraint */
155  );
156 
157 /** gets array of variables in SOS1 constraint */
158 SCIP_EXPORT
160  SCIP* scip, /**< SCIP data structure */
161  SCIP_CONS* cons /**< constraint data */
162  );
163 
164 /** gets array of weights in SOS1 constraint (or NULL if not existent) */
165 SCIP_EXPORT
167  SCIP* scip, /**< SCIP data structure */
168  SCIP_CONS* cons /**< constraint data */
169  );
170 
171 /** gets conflict graph of SOS1 constraints (or NULL if not existent)
172  *
173  * @note The conflict graph is globally valid; local changes are not taken into account.
174  */
175 SCIP_EXPORT
177  SCIP_CONSHDLR* conshdlr /**< SOS1 constraint handler */
178  );
179 
180 /** gets number of problem variables that are part of the SOS1 conflict graph */
181 SCIP_EXPORT
182 int SCIPgetNSOS1Vars(
183  SCIP_CONSHDLR* conshdlr /**< SOS1 constraint handler */
184  );
185 
186 /** returns whether variable is part of the SOS1 conflict graph */
187 SCIP_EXPORT
189  SCIP_CONSHDLR* conshdlr, /**< SOS1 constraint handler */
190  SCIP_VAR* var /**< variable */
191  );
192 
193 /** returns node of variable in the conflict graph or -1 if variable is not part of the SOS1 conflict graph */
194 SCIP_EXPORT
196  SCIP_CONSHDLR* conshdlr, /**< SOS1 constraint handler */
197  SCIP_VAR* var /**< variable */
198  );
199 
200 /** returns variable that belongs to a given node from the conflict graph */
201 SCIP_EXPORT
203  SCIP_DIGRAPH* conflictgraph, /**< conflict graph */
204  int node /**< node from the conflict graph */
205  );
206 
207 /** based on solution values of the variables, fixes variables to zero to turn all SOS1 constraints feasible */
208 SCIP_EXPORT
210  SCIP* scip, /**< SCIP pointer */
211  SCIP_CONSHDLR* conshdlr, /**< SOS1 constraint handler */
212  SCIP_SOL* sol, /**< solution */
213  SCIP_Bool* changed, /**< pointer to store whether the solution has been changed */
214  SCIP_Bool* success /**< pointer to store whether SOS1 constraints have been turned feasible and
215  * solution was good enough */
216  );
217 
218 /** @} */
219 
220 /** @} */
221 
222 #ifdef __cplusplus
223 }
224 #endif
225 
226 #endif
type definitions for miscellaneous datastructures
SCIP_VAR ** SCIPgetVarsSOS1(SCIP *scip, SCIP_CONS *cons)
Definition: cons_sos1.c:10639
SCIP_Real * SCIPgetWeightsSOS1(SCIP *scip, SCIP_CONS *cons)
Definition: cons_sos1.c:10664
SCIP_RETCODE SCIPmakeSOS1sFeasible(SCIP *scip, SCIP_CONSHDLR *conshdlr, SCIP_SOL *sol, SCIP_Bool *changed, SCIP_Bool *success)
Definition: cons_sos1.c:10816
int SCIPgetNSOS1Vars(SCIP_CONSHDLR *conshdlr)
Definition: cons_sos1.c:10714
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_RETCODE SCIPincludeConshdlrSOS1(SCIP *scip)
Definition: cons_sos1.c:10195
type definitions for return codes for SCIP methods
int SCIPvarGetNodeSOS1(SCIP_CONSHDLR *conshdlr, SCIP_VAR *var)
Definition: cons_sos1.c:10760
SCIP_RETCODE SCIPaddVarSOS1(SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var, SCIP_Real weight)
Definition: cons_sos1.c:10547
type definitions for SCIP&#39;s main datastructure
type definitions for problem variables
SCIP_DIGRAPH * SCIPgetConflictgraphSOS1(SCIP_CONSHDLR *conshdlr)
Definition: cons_sos1.c:10692
SCIP_Bool SCIPvarIsSOS1(SCIP_CONSHDLR *conshdlr, SCIP_VAR *var)
Definition: cons_sos1.c:10736
SCIP_RETCODE SCIPappendVarSOS1(SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var)
Definition: cons_sos1.c:10581
#define SCIP_Bool
Definition: def.h:93
int SCIPgetNVarsSOS1(SCIP *scip, SCIP_CONS *cons)
Definition: cons_sos1.c:10614
SCIP_VAR * SCIPnodeGetVarSOS1(SCIP_DIGRAPH *conflictgraph, int node)
Definition: cons_sos1.c:10791
type definitions for storing primal CIP solutions
SCIP_RETCODE SCIPcreateConsBasicSOS1(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, SCIP_Real *weights)
Definition: cons_sos1.c:10531
#define SCIP_Real
Definition: def.h:186
SCIP_RETCODE SCIPcreateConsSOS1(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, SCIP_Real *weights, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode)
Definition: cons_sos1.c:10410
common defines and data types used in all packages of SCIP
type definitions for constraints and constraint handlers