Scippy

SCIP

Solving Constraint Integer Programs

struct_var.h
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2 /* */
3 /* This file is part of the program and library */
4 /* SCIP --- Solving Constraint Integer Programs */
5 /* */
6 /* Copyright (C) 2002-2014 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 struct_var.h
17  * @brief datastructures for problem variables
18  * @author Tobias Achterberg
19  */
20 
21 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
22 
23 #ifndef __SCIP_STRUCT_VAR_H__
24 #define __SCIP_STRUCT_VAR_H__
25 
26 
27 #include "scip/def.h"
28 #include "scip/type_history.h"
29 #include "scip/type_event.h"
30 #include "scip/type_var.h"
31 #include "scip/type_implics.h"
32 #include "scip/type_cons.h"
33 #include "scip/type_prop.h"
34 
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 
39 /** hole in a domain */
40 struct SCIP_Hole
41 {
42  SCIP_Real left; /**< left bound of open interval defining the hole (left,right) */
43  SCIP_Real right; /**< right bound of open interval defining the hole (left,right) */
44 };
45 
46 /** list of domain holes */
47 struct SCIP_Holelist
48 {
49  SCIP_HOLE hole; /**< this hole */
50  SCIP_HOLELIST* next; /**< next hole in list */
51 };
52 
53 /** change in a hole list */
54 struct SCIP_HoleChg
55 {
56  SCIP_HOLELIST** ptr; /**< changed list pointer */
57  SCIP_HOLELIST* newlist; /**< new value of list pointer */
58  SCIP_HOLELIST* oldlist; /**< old value of list pointer */
59 };
60 
61 /** data for branching decision bound changes */
62 struct SCIP_BranchingData
63 {
64  SCIP_Real lpsolval; /**< sol val of var in last LP prior to bound change, or SCIP_INVALID if unknown */
65 };
66 
67 /** data for infered bound changes */
68 struct SCIP_InferenceData
69 {
70  SCIP_VAR* var; /**< variable that was changed (parent of var, or var itself) */
71  union
72  {
73  SCIP_CONS* cons; /**< constraint that infered this bound change, or NULL */
74  SCIP_PROP* prop; /**< propagator that infered this bound change, or NULL */
75  } reason;
76  int info; /**< user information for inference to help resolving the conflict */
77 };
78 
79 /** change in one bound of a variable */
80 struct SCIP_BoundChg
81 {
82  SCIP_Real newbound; /**< new value for bound */
83  union
84  {
85  SCIP_BRANCHINGDATA branchingdata; /**< data for branching decisions */
86  SCIP_INFERENCEDATA inferencedata; /**< data for infered bound changes */
87  } data;
88  SCIP_VAR* var; /**< active variable to change the bounds for */
89  unsigned int boundchgtype:2; /**< bound change type: branching decision or infered bound change */
90  unsigned int boundtype:1; /**< type of bound for var: lower or upper bound */
91  unsigned int inferboundtype:1; /**< type of bound for inference var (see inference data): lower or upper bound */
92  unsigned int applied:1; /**< was this bound change applied at least once? */
93  unsigned int redundant:1; /**< is this bound change redundant? */
94 };
95 
96 /** bound change index representing the time of the bound change in path from root to current node */
97 struct SCIP_BdChgIdx
98 {
99  int depth; /**< depth of node where the bound change was created */
100  int pos; /**< position of bound change in node's domchg array */
101 };
102 
103 /** bound change information to track bound changes from root node to current node */
104 struct SCIP_BdChgInfo
105 {
106  SCIP_Real oldbound; /**< old value for bound */
107  SCIP_Real newbound; /**< new value for bound */
108  SCIP_VAR* var; /**< active variable that changed the bounds */
109  SCIP_INFERENCEDATA inferencedata; /**< data for infered bound changes */
110  SCIP_BDCHGIDX bdchgidx; /**< bound change index in path from root to current node */
111  unsigned int pos:27; /**< position in the variable domain change array */
112  unsigned int boundchgtype:2; /**< bound change type: branching decision or infered bound change */
113  unsigned int boundtype:1; /**< type of bound for var: lower or upper bound */
114  unsigned int inferboundtype:1; /**< type of bound for inference var (see inference data): lower or upper bound */
115  unsigned int redundant:1; /**< does the bound change info belong to a redundant bound change? */
116 };
117 
118 /** tracks changes of the variables' domains (static arrays, bound changes only) */
119 struct SCIP_DomChgBound
120 {
121  unsigned int nboundchgs:30; /**< number of bound changes (must be first structure entry!) */
122  unsigned int domchgtype:2; /**< type of domain change data (must be first structure entry!) */
123  SCIP_BOUNDCHG* boundchgs; /**< array with changes in bounds of variables */
124 };
125 
126 /** tracks changes of the variables' domains (static arrays, bound and hole changes) */
127 struct SCIP_DomChgBoth
128 {
129  unsigned int nboundchgs:30; /**< number of bound changes (must be first structure entry!) */
130  unsigned int domchgtype:2; /**< type of domain change data (must be first structure entry!) */
131  SCIP_BOUNDCHG* boundchgs; /**< array with changes in bounds of variables */
132  SCIP_HOLECHG* holechgs; /**< array with changes in hole lists */
133  int nholechgs; /**< number of hole list changes */
134 };
135 
136 /** tracks changes of the variables' domains (dynamic arrays) */
137 struct SCIP_DomChgDyn
138 {
139  unsigned int nboundchgs:30; /**< number of bound changes (must be first structure entry!) */
140  unsigned int domchgtype:2; /**< type of domain change data (must be first structure entry!) */
141  SCIP_BOUNDCHG* boundchgs; /**< array with changes in bounds of variables */
142  SCIP_HOLECHG* holechgs; /**< array with changes in hole lists */
143  int nholechgs; /**< number of hole list changes */
144  int boundchgssize; /**< size of bound changes array */
145  int holechgssize; /**< size of hole changes array */
146 };
147 
148 /** tracks changes of the variables' domains */
149 union SCIP_DomChg
150 {
151  SCIP_DOMCHGBOUND domchgbound; /**< bound changes */
152  SCIP_DOMCHGBOTH domchgboth; /**< bound and hole changes */
153  SCIP_DOMCHGDYN domchgdyn; /**< bound and hole changes with dynamic arrays */
154 };
155 
156 /** domain of a variable */
157 struct SCIP_Dom
158 {
159  SCIP_Real lb; /**< lower bounds of variables */
160  SCIP_Real ub; /**< upper bounds of variables */
161  SCIP_HOLELIST* holelist; /**< list of holes */
162 };
163 
164 /** original variable information */
165 struct SCIP_Original
166 {
167  SCIP_DOM origdom; /**< domain of variable in original problem */
168  SCIP_VAR* transvar; /**< pointer to representing transformed variable */
169 };
170 
171 /** aggregation information: x = a*y + c */
172 struct SCIP_Aggregate
173 {
174  SCIP_Real scalar; /**< multiplier a in aggregation */
175  SCIP_Real constant; /**< constant shift c in aggregation */
176  SCIP_VAR* var; /**< variable y in aggregation */
177 };
178 
179 /** multiple aggregation information: x = a_1*y_1 + ... + a_k*y_k + c */
180 struct SCIP_Multaggr
181 {
182  SCIP_Real constant; /**< constant shift c in multiple aggregation */
183  SCIP_Real* scalars; /**< multipliers a in multiple aggregation */
184  SCIP_VAR** vars; /**< variables y in multiple aggregation */
185  int nvars; /**< number of variables in aggregation */
186  int varssize; /**< size of vars and scalars arrays */
187 };
188 
189 /** negation information: x' = c - x */
190 struct SCIP_Negate
191 {
192  SCIP_Real constant; /**< constant shift c in negation */
193 };
194 
195 /** variable of the problem */
196 struct SCIP_Var
197 {
198 #ifndef NDEBUG
199  SCIP* scip; /**< SCIP data structure */
200 #endif
201  SCIP_Real obj; /**< objective function value of variable */
202  SCIP_Real branchfactor; /**< factor to weigh variable's branching score with */
203  SCIP_Real rootsol; /**< last primal solution of variable in root node, or zero */
204  SCIP_Real bestrootsol; /**< best primal solution of variable in root node, or zero, w.r.t. root LP value and root reduced cost */
205  SCIP_Real bestrootredcost; /**< best reduced costs of variable in root node, or zero, w.r.t. root LP value and root solution value */
206  SCIP_Real bestrootlpobjval; /**< best root LP objective value, or SCIP_INVALID, w.r.t. root solution value and root reduced cost */
207  SCIP_Real relaxsol; /**< primal solution of variable in current relaxation solution, or SCIP_INVALID */
208  SCIP_Real nlpsol; /**< primal solution of variable in current NLP solution, or SCIP_INVALID */
209  SCIP_Real primsolavg; /**< weighted average of all values of variable in primal feasible solutions */
210  SCIP_Real conflictlb; /**< maximal lower bound of variable in the current conflict */
211  SCIP_Real conflictub; /**< minimal upper bound of variable in the current conflict */
212  SCIP_Real conflictrelaxedlb; /**< minimal relaxed lower bound of variable in the current conflict (conflictrelqxlb <= conflictlb) */
213  SCIP_Real conflictrelaxedub; /**< minimal release upper bound of variable in the current conflict (conflictrelqxlb <= conflictlb) */
214  SCIP_Real lazylb; /**< global lower bound that is ensured by constraints and has not to be added to the LP */
215  SCIP_Real lazyub; /**< global upper bound that is ensured by constraints and has not to be added to the LP */
216  SCIP_DOM glbdom; /**< domain of variable in global problem */
217  SCIP_DOM locdom; /**< domain of variable in current subproblem */
218  union
219  {
220  SCIP_ORIGINAL original; /**< original variable information */
221  SCIP_COL* col; /**< LP column (for column variables) */
222  SCIP_AGGREGATE aggregate; /**< aggregation information (for aggregated variables) */
223  SCIP_MULTAGGR multaggr; /**< multiple aggregation information (for multiple aggregated variables) */
224  SCIP_NEGATE negate; /**< negation information (for negated variables) */
225  } data;
226  char* name; /**< name of the variable */
227  SCIP_DECL_VARCOPY ((*varcopy)); /**< copies variable data if wanted to subscip, or NULL */
228  SCIP_DECL_VARDELORIG ((*vardelorig)); /**< frees user data of original variable */
229  SCIP_DECL_VARTRANS ((*vartrans)); /**< creates transformed user data by transforming original user data */
230  SCIP_DECL_VARDELTRANS ((*vardeltrans)); /**< frees user data of transformed variable */
231  SCIP_VARDATA* vardata; /**< user data for this specific variable */
232  SCIP_VAR** parentvars; /**< parent variables in the aggregation tree */
233  SCIP_VAR* negatedvar; /**< pointer to the variables negation: x' = lb + ub - x, or NULL if not created */
234  SCIP_VBOUNDS* vlbs; /**< variable lower bounds x >= b*y + d */
235  SCIP_VBOUNDS* vubs; /**< variable upper bounds x <= b*y + d */
236  SCIP_IMPLICS* implics; /**< implications y >=/<= b following from x <= 0 and x >= 1 (x binary), or NULL if x is not binary */
237  SCIP_CLIQUELIST* cliquelist; /**< list of cliques the variable and its negation is member of */
238  SCIP_EVENTFILTER* eventfilter; /**< event filter for events concerning this variable; not for ORIGINAL vars */
239  SCIP_BDCHGINFO* lbchginfos; /**< bound change informations for lower bound changes from root to current node */
240  SCIP_BDCHGINFO* ubchginfos; /**< bound change informations for upper bound changes from root to current node */
241  SCIP_HISTORY* history; /**< branching and inference history information */
242  SCIP_HISTORY* historycrun; /**< branching and inference history information for current run */
243  SCIP_VALUEHISTORY* valuehistory; /**< branching and inference history information which are value based, or NULL if not used */
244  SCIP_Longint closestvblpcount; /**< LP count for which the closestvlbidx/closestvubidx entries are valid */
245  int index; /**< consecutively numbered variable identifier */
246  int probindex; /**< array position in problems vars array, or -1 if not assigned to a problem */
247  int pseudocandindex; /**< array position in pseudo branching candidates array, or -1 */
248  int eventqueueindexobj; /**< array position in event queue of objective change event, or -1 */
249  int eventqueueindexlb; /**< array position in event queue of lower bound change event, or -1 */
250  int eventqueueindexub; /**< array position in event queue of upper bound change event, or -1 */
251  int parentvarssize; /**< available slots in parentvars array */
252  int nparentvars; /**< number of parent variables in aggregation tree (used slots of parentvars) */
253  int nuses; /**< number of times, this variable is referenced */
254  int nlocksdown; /**< number of locks for rounding down; if zero, rounding down is always feasible */
255  int nlocksup; /**< number of locks for rounding up; if zero, rounding up is always feasible */
256  int branchpriority; /**< priority of the variable for branching */
257  int lbchginfossize; /**< available slots in lbchginfos array */
258  int nlbchginfos; /**< number of lower bound changes from root node to current node */
259  int ubchginfossize; /**< available slots in ubchginfos array */
260  int nubchginfos; /**< number of upper bound changes from root node to current node */
261  int conflictlbcount; /**< number of last conflict, the lower bound was member of */
262  int conflictubcount; /**< number of last conflict, the upper bound was member of */
263  int closestvlbidx; /**< index of closest VLB variable in current LP solution, or -1 */
264  int closestvubidx; /**< index of closest VUB variable in current LP solution, or -1 */
265  unsigned int initial:1; /**< TRUE iff var's column should be present in the initial root LP */
266  unsigned int removable:1; /**< TRUE iff var's column is removable from the LP (due to aging or cleanup) */
267  unsigned int deletable:1; /**< TRUE iff the variable is removable from the problem */
268  unsigned int deleted:1; /**< TRUE iff variable was marked for deletion from the problem */
269  unsigned int donotmultaggr:1; /**< TRUE iff variable is not allowed to be multi-aggregated */
270  unsigned int vartype:2; /**< type of variable: binary, integer, implicit integer, continuous */
271  unsigned int varstatus:3; /**< status of variable: original, loose, column, fixed, aggregated, multiaggregated, negated */
272  unsigned int pseudocostflag:2; /**< temporary flag used in pseudo cost update */
273  unsigned int branchdirection:2; /**< preferred branching direction of the variable (downwards, upwards, auto) */
274  unsigned int eventqueueimpl:1; /**< is an IMPLADDED event on this variable currently in the event queue? */
275 };
276 
277 #ifdef __cplusplus
278 }
279 #endif
280 
281 #endif
282