Scippy

SCIP

Solving Constraint Integer Programs

heur_conflictdiving.c
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 2002-2022 Zuse Institute Berlin */
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 heur_conflictdiving.c
26  * @ingroup DEFPLUGINS_HEUR
27  * @brief LP diving heuristic that chooses fixings w.r.t. conflict locks
28  * @author Jakob Witzig
29  */
30 
31 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32 
34 #include "scip/heuristics.h"
35 #include "scip/pub_heur.h"
36 #include "scip/pub_message.h"
37 #include "scip/pub_misc.h"
38 #include "scip/pub_var.h"
39 #include "scip/scip_heur.h"
40 #include "scip/scip_mem.h"
41 #include "scip/scip_numerics.h"
42 #include "scip/scip_param.h"
43 #include "scip/scip_sol.h"
44 #include "scip/scip_solvingstats.h"
45 #include <string.h>
46 
47 #define HEUR_NAME "conflictdiving"
48 #define HEUR_DESC "LP diving heuristic that chooses fixings w.r.t. conflict locks"
49 #define HEUR_DISPCHAR SCIP_HEURDISPCHAR_DIVING
50 #define HEUR_PRIORITY -1000100
51 #define HEUR_FREQ 10
52 #define HEUR_FREQOFS 0
53 #define HEUR_MAXDEPTH -1
54 #define HEUR_TIMING SCIP_HEURTIMING_AFTERLPPLUNGE
55 #define HEUR_USESSUBSCIP FALSE /**< does the heuristic use a secondary SCIP instance? */
56 #define DIVESET_DIVETYPES SCIP_DIVETYPE_INTEGRALITY | SCIP_DIVETYPE_SOS1VARIABLE /**< bit mask that represents all supported dive types */
57 #define DIVESET_ISPUBLIC FALSE /**< is this dive set publicly available (ie., can be used by other primal heuristics?) */
58 #define DEFAULT_RANDSEED 151 /**< default random seed */
59 
60 /*
61  * Default parameter settings
62  */
63 
64 #define DEFAULT_MINRELDEPTH 0.0 /**< minimal relative depth to start diving */
65 #define DEFAULT_MAXRELDEPTH 1.0 /**< maximal relative depth to start diving */
66 #define DEFAULT_MAXLPITERQUOT 0.15 /**< maximal fraction of diving LP iterations compared to node LP iterations */
67 #define DEFAULT_MAXLPITEROFS 1000 /**< additional number of allowed LP iterations */
68 #define DEFAULT_MAXDIVEUBQUOT 0.8 /**< maximal quotient (curlowerbound - lowerbound)/(cutoffbound - lowerbound)
69  * where diving is performed (0.0: no limit) */
70 #define DEFAULT_MAXDIVEAVGQUOT 0.0 /**< maximal quotient (curlowerbound - lowerbound)/(avglowerbound - lowerbound)
71  * where diving is performed (0.0: no limit) */
72 #define DEFAULT_MAXDIVEUBQUOTNOSOL 0.1 /**< maximal UBQUOT when no solution was found yet (0.0: no limit) */
73 #define DEFAULT_MAXDIVEAVGQUOTNOSOL 0.0 /**< maximal AVGQUOT when no solution was found yet (0.0: no limit) */
74 #define DEFAULT_BACKTRACK TRUE /**< use one level of backtracking if infeasibility is encountered? */
75 #define DEFAULT_LPRESOLVEDOMCHGQUOT 0.15/**< percentage of immediate domain changes during probing to trigger LP resolve */
76 #define DEFAULT_LPSOLVEFREQ 0 /**< LP solve frequency for diving heuristics */
77 #define DEFAULT_ONLYLPBRANCHCANDS FALSE /**< should only LP branching candidates be considered instead of the slower but
78  * more general constraint handler diving variable selection? */
79 #define DEFAULT_LOCKWEIGHT 0.75 /**< weight used in a convex combination of conflict and variable locks */
80 #define DEFAULT_LIKECOEF FALSE /**< perform rounding like coefficient diving */
81 #define DEFAULT_MAXVIOL TRUE /**< prefer rounding direction with most violation */
82 #define DEFAULT_MINCONFLICTLOCKS 5 /**< threshold for penalizing the score */
83 
84 /* locally defined heuristic data */
85 struct SCIP_HeurData
86 {
87  SCIP_SOL* sol; /**< working solution */
88  SCIP_Real lockweight; /**< weight factor to combine conflict and variable locks */
89  SCIP_Bool likecoefdiving; /**< use the same rounding strategy like coefficent diving */
90  SCIP_Bool maxviol; /**< rounding into potentially infeasible direction */
91  int minconflictlocks; /**< threshold for penalizing the score */
92 };
93 
94 /*
95  * Callback methods
96  */
97 
98 /** copy method for primal heuristic plugins (called when SCIP copies plugins) */
99 static
100 SCIP_DECL_HEURCOPY(heurCopyConflictdiving)
101 { /*lint --e{715}*/
102  assert(scip != NULL);
103  assert(heur != NULL);
104  assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0);
105 
106  /* call inclusion method of constraint handler */
108 
109  return SCIP_OKAY;
110 }
111 
112 /** destructor of primal heuristic to free user data (called when SCIP is exiting) */
113 static
114 SCIP_DECL_HEURFREE(heurFreeConflictdiving) /*lint --e{715}*/
115 { /*lint --e{715}*/
116  SCIP_HEURDATA* heurdata;
118  assert(heur != NULL);
119  assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0);
120  assert(scip != NULL);
121 
122  /* free heuristic data */
123  heurdata = SCIPheurGetData(heur);
124  assert(heurdata != NULL);
125 
126  SCIPfreeBlockMemory(scip, &heurdata);
127  SCIPheurSetData(heur, NULL);
128 
129  return SCIP_OKAY;
130 }
131 
132 
133 /** initialization method of primal heuristic (called after problem was transformed) */
134 static
135 SCIP_DECL_HEURINIT(heurInitConflictdiving) /*lint --e{715}*/
136 { /*lint --e{715}*/
137  SCIP_HEURDATA* heurdata;
139  assert(heur != NULL);
140  assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0);
141 
142  /* get heuristic data */
143  heurdata = SCIPheurGetData(heur);
144  assert(heurdata != NULL);
145 
146  /* create working solution */
147  SCIP_CALL( SCIPcreateSol(scip, &heurdata->sol, heur) );
148 
149  return SCIP_OKAY;
150 }
151 
152 
153 /** deinitialization method of primal heuristic (called before transformed problem is freed) */
154 static
155 SCIP_DECL_HEUREXIT(heurExitConflictdiving) /*lint --e{715}*/
156 { /*lint --e{715}*/
157  SCIP_HEURDATA* heurdata;
159  assert(heur != NULL);
160  assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0);
161 
162  /* get heuristic data */
163  heurdata = SCIPheurGetData(heur);
164  assert(heurdata != NULL);
165 
166  /* free working solution */
167  SCIP_CALL( SCIPfreeSol(scip, &heurdata->sol) );
168 
169  return SCIP_OKAY;
170 }
171 
172 /** execution method of primal heuristic */
173 static
174 SCIP_DECL_HEUREXEC(heurExecConflictdiving) /*lint --e{715}*/
175 { /*lint --e{715}*/
176  SCIP_HEURDATA* heurdata;
177  SCIP_DIVESET* diveset;
178 
179  heurdata = SCIPheurGetData(heur);
180  assert(heurdata != NULL);
181 
182  assert(SCIPheurGetNDivesets(heur) > 0);
183  assert(SCIPheurGetDivesets(heur) != NULL);
184  diveset = SCIPheurGetDivesets(heur)[0];
185  assert(diveset != NULL);
186 
187  *result = SCIP_DELAYED;
188 
189  /* don't run if no conflict constraints where found */
190  if( SCIPgetNConflictConssFound(scip) == 0 )
191  return SCIP_OKAY;
192 
193  SCIP_CALL( SCIPperformGenericDivingAlgorithm(scip, diveset, heurdata->sol, heur, result, nodeinfeasible, -1L, SCIP_DIVECONTEXT_SINGLE) );
194 
195  return SCIP_OKAY;
196 }
197 
198 #define MIN_RAND 1e-06
199 #define MAX_RAND 1e-05
200 
201 /** calculate score variant 1: use rounding strategy like coefficent diving */
202 static
204  SCIP* scip, /**< SCIP data structure */
205  SCIP_HEURDATA* heurdata, /**< heuristic data */
206  SCIP_RANDNUMGEN* rng, /**< random number generator of the diveset */
207  SCIP_DIVETYPE divetype, /**< divetype of the heuristic */
208  SCIP_VAR* cand, /**< diving candidate */
209  SCIP_Real candsol, /**< diving candidate solution */
210  SCIP_Real candsfrac, /**< fractionality of the candidate solution */
211  SCIP_Real* score, /**< pointer to store the score */
212  SCIP_Bool* roundup /**< pointer to store whether the candidate should be rounded upwards */
213  )
214 {
215  SCIP_Real upweight;
216  SCIP_Real downweight;
217  SCIP_Bool mayrounddown;
218  SCIP_Bool mayroundup;
219  int nconflictlocksdown;
220  int nconflictlocksup;
221  int nlocksdown;
222  int nlocksup;
223 
224  /* get conflict locks */
225  nconflictlocksup = SCIPvarGetNLocksUpType(cand, SCIP_LOCKTYPE_CONFLICT);
226  nconflictlocksdown = SCIPvarGetNLocksDownType(cand, SCIP_LOCKTYPE_CONFLICT);
227 
228  /* get variable locks */
230  nlocksdown = SCIPvarGetNLocksDownType(cand, SCIP_LOCKTYPE_MODEL);
231 
232  /* combine conflict and variable locks */
233  upweight = heurdata->lockweight * nconflictlocksup + (1.0 - heurdata->lockweight) * nlocksup;
234  downweight = heurdata->lockweight * nconflictlocksdown + (1.0 - heurdata->lockweight) * nlocksdown;
235 
236  /* check whether there exists a direction w/o any locks */
237  mayrounddown = SCIPisZero(scip, upweight);
238  mayroundup = SCIPisZero(scip, downweight);
239 
240  if( mayrounddown || mayroundup )
241  {
242  /* choose rounding direction:
243  * - if variable may be rounded in both directions, round corresponding to the fractionality
244  * - otherwise, round in the infeasible direction
245  */
246  if( mayrounddown && mayroundup )
247  {
248  assert(divetype != SCIP_DIVETYPE_SOS1VARIABLE || heurdata->lockweight > 0);
249 
250  /* try to avoid variability; decide randomly if the LP solution can contain some noise */
251  if( SCIPisEQ(scip, candsfrac, 0.5) )
252  *roundup = (SCIPrandomGetInt(rng, 0, 1) == 0);
253  else
254  *roundup = (candsfrac > 0.5);
255  }
256  else
257  *roundup = mayrounddown;
258  }
259  else
260  {
261  /* the candidate may not be rounded */
262  *roundup = (SCIPisGT(scip, downweight, upweight) || (SCIPisEQ(scip, downweight, upweight) && candsfrac > 0.5));
263  }
264 
265  if( *roundup )
266  {
267  switch( divetype )
268  {
270  candsfrac = 1.0 - candsfrac;
271  break;
273  if( SCIPisFeasPositive(scip, candsol) )
274  candsfrac = 1.0 - candsfrac;
275  break;
276  default:
277  SCIPerrorMessage("Error: Unsupported diving type\n");
278  SCIPABORT();
279  return SCIP_INVALIDDATA; /*lint !e527*/
280  } /*lint !e788*/
281 
282  /* add some noise to avoid ties */
283  *score = upweight + SCIPrandomGetReal(rng, MIN_RAND, MAX_RAND);
284  }
285  else
286  {
287  if( divetype == SCIP_DIVETYPE_SOS1VARIABLE && SCIPisFeasNegative(scip, candsol) )
288  candsfrac = 1.0 - candsfrac;
289 
290  /* add some noise to avoid ties */
291  *score = downweight + SCIPrandomGetReal(rng, MIN_RAND, MAX_RAND);
292  }
293 
294  /* penalize too small fractions */
295  if( SCIPisEQ(scip, candsfrac, 0.01) )
296  {
297  /* try to avoid variability; decide randomly if the LP solution can contain some noise.
298  * use a 1:SCIP_PROBINGSCORE_PENALTYRATIO chance for scaling the score
299  */
301  (*score) *= 0.01;
302  }
303  else if( candsfrac < 0.01 )
304  (*score) *= 0.1;
305 
306  /* prefer decisions on binary variables */
307  if( !SCIPvarIsBinary(cand) )
308  *score = -1.0 / *score;
309 
310  return SCIP_OKAY;
311 }
312 
313 /** calculate score variant 2: use a rounding strategy that tends towards infeasibility */
314 static
316  SCIP* scip, /**< SCIP data structure */
317  SCIP_HEURDATA* heurdata, /**< heuristic data */
318  SCIP_RANDNUMGEN* rng, /**< random number generator of the diveset */
319  SCIP_DIVETYPE divetype, /**< divetype of the heuristic */
320  SCIP_VAR* cand, /**< diving candidate */
321  SCIP_Real candsol, /**< diving candidate solution */
322  SCIP_Real candsfrac, /**< fractionality of the candidate solution */
323  SCIP_Real* score, /**< pointer to store the score */
324  SCIP_Bool* roundup /**< pointer to store whether the candidate should be rounded upwards */
325  )
326 {
327  SCIP_Real conflictlocksum;
328  SCIP_Real upweight;
329  SCIP_Real downweight;
330  SCIP_Bool mayrounddown;
331  SCIP_Bool mayroundup;
332  int nlocksup;
333  int nlocksdown;
334  int nconflictlocksup;
335  int nconflictlocksdown;
336 
337  assert(scip != NULL);
338  assert(heurdata != NULL);
339  assert(rng != NULL);
340 
341  /* get conflict locks */
342  nconflictlocksup = SCIPvarGetNLocksUpType(cand, SCIP_LOCKTYPE_CONFLICT);
343  nconflictlocksdown = SCIPvarGetNLocksDownType(cand, SCIP_LOCKTYPE_CONFLICT);
344  conflictlocksum = nconflictlocksup + nconflictlocksdown;
345 
346  /* get variable locks */
348  nlocksdown = SCIPvarGetNLocksDownType(cand, SCIP_LOCKTYPE_MODEL);
349 
350  /* combine conflict and variable locks */
351  upweight = heurdata->lockweight * nconflictlocksup + (1.0 - heurdata->lockweight) * nlocksup;
352  downweight = heurdata->lockweight * nconflictlocksdown + (1.0 - heurdata->lockweight) * nlocksdown;
353 
354  /* check whether there exists a rounding direction w/o any locks */
355  mayrounddown = SCIPisZero(scip, upweight);
356  mayroundup = SCIPisZero(scip, downweight);
357 
358  /* variable can be rounded in exactly one direction and we try to go into the feasible direction */
359  if( mayrounddown || mayroundup )
360  {
361  /* choose rounding direction:
362  * - if variable may be rounded in both directions, round corresponding to the fractionality
363  * - otherwise, round in the feasible direction
364  */
365  if( mayrounddown && mayroundup )
366  {
367  assert(divetype != SCIP_DIVETYPE_SOS1VARIABLE || heurdata->lockweight > 0);
368 
369  /* try to avoid variability; decide randomly if the LP solution can contain some noise */
370  if( SCIPisEQ(scip, candsfrac, 0.5) )
371  *roundup = (SCIPrandomGetInt(rng, 0, 1) == 0);
372  else
373  *roundup = (candsfrac > 0.5);
374  }
375  else
376  *roundup = mayroundup;
377  }
378  else
379  {
380  assert(!mayrounddown);
381 
382  /* both rounding directions have a different amount of locks */
383  if( !SCIPisEQ(scip, upweight, downweight) )
384  {
385  *roundup = (heurdata->maxviol ? SCIPisGT(scip, upweight, downweight) : SCIPisLT(scip, upweight, downweight));
386  }
387  /* break ties with lp fractionality != 0.5 */
388  else if( !SCIPisEQ(scip, candsfrac, 0.5) )
389  {
390  *roundup = (candsfrac > 0.5);
391  }
392  /* break tie randomly */
393  else
394  {
395  *roundup = (SCIPrandomGetInt(rng, 0, 1) == 1);
396  }
397  }
398 
399  if( *roundup )
400  {
401  switch( divetype )
402  {
404  candsfrac = 1.0 - candsfrac;
405  break;
407  if( SCIPisFeasPositive(scip, candsol) )
408  candsfrac = 1.0 - candsfrac;
409  break;
410  default:
411  SCIPerrorMessage("Error: Unsupported diving type\n");
412  SCIPABORT();
413  return SCIP_INVALIDDATA; /*lint !e527*/
414  } /*lint !e788*/
415 
416  /* add some noise to avoid ties */
417  *score = upweight + SCIPrandomGetReal(rng, MIN_RAND, MAX_RAND);
418  }
419  else
420  {
421  if( divetype == SCIP_DIVETYPE_SOS1VARIABLE && SCIPisFeasNegative(scip, candsol) )
422  candsfrac = 1.0 - candsfrac;
423 
424  /* add some noise to avoid ties */
425  *score = downweight + SCIPrandomGetReal(rng, MIN_RAND, MAX_RAND);
426  }
427 
428  /* penalize too few conflict locks */
429  if( conflictlocksum > 0 && conflictlocksum < heurdata->minconflictlocks )
430  (*score) *= 0.1;
431 
432  /* penalize if no conflict locks exist at all */
433  if( conflictlocksum == 0 )
434  (*score) *= 0.01;
435 
436  /* penalize too small fractions */
437  if( SCIPisEQ(scip, candsfrac, 0.01) )
438  {
439  /* try to avoid variability; decide randomly if the LP solution can contain some noise.
440  * use a 1:SCIP_PROBINGSCORE_PENALTYRATIO chance for scaling the score
441  */
443  (*score) *= 0.01;
444  }
445  else if( candsfrac < 0.01 )
446  (*score) *= 0.01;
447 
448  /* prefer decisions on binary variables */
449  if( !SCIPvarIsBinary(cand) )
450  *score = -1.0 / *score;
451 
452  return SCIP_OKAY;
453 }
454 
455 
456 /** returns a score for the given candidate -- the best candidate maximizes the diving score */
457 static
458 SCIP_DECL_DIVESETGETSCORE(divesetGetScoreConflictdiving)
459 {
460  SCIP_HEUR* heur;
461  SCIP_HEURDATA* heurdata;
462  SCIP_RANDNUMGEN* rng;
463 
464  rng = SCIPdivesetGetRandnumgen(diveset);
465  assert(rng != NULL);
466 
467  heur = SCIPdivesetGetHeur(diveset);
468  assert(heur != NULL);
469 
470  heurdata = SCIPheurGetData(heur);
471  assert(heurdata != NULL);
472 
473  if( heurdata->likecoefdiving )
474  {
475  SCIP_CALL( getScoreLikeCoefdiving(scip, heurdata, rng, divetype, cand, candsol, candsfrac, score, roundup) );
476  }
477  else
478  {
479  SCIP_CALL( getScore(scip, heurdata, rng, divetype, cand, candsol, candsfrac, score, roundup) );
480  }
481 
482  /* check, if candidate is new best candidate: prefer unroundable candidates in any case */
483  assert( (0.0 < candsfrac && candsfrac < 1.0) || SCIPvarIsBinary(cand) || divetype == SCIP_DIVETYPE_SOS1VARIABLE );
484 
485  return SCIP_OKAY;
486 }
487 
488 /*
489  * heuristic specific interface methods
490  */
491 
492 #define divesetAvailableConflictdiving NULL
493 
494 /** creates the conflictdiving heuristic and includes it in SCIP */
496  SCIP* scip /**< SCIP data structure */
497  )
498 {
499  SCIP_HEURDATA* heurdata;
500  SCIP_HEUR* heur;
501 
502  /* create conflictdiving primal heuristic data */
503  SCIP_CALL( SCIPallocBlockMemory(scip, &heurdata) );
504 
505  /* include primal heuristic */
507  HEUR_FREQOFS, HEUR_MAXDEPTH, HEUR_TIMING, HEUR_USESSUBSCIP, heurExecConflictdiving, heurdata) );
508 
509  assert(heur != NULL);
510 
511  /* set non-NULL pointers to callback methods */
512  SCIP_CALL( SCIPsetHeurCopy(scip, heur, heurCopyConflictdiving) );
513  SCIP_CALL( SCIPsetHeurFree(scip, heur, heurFreeConflictdiving) );
514  SCIP_CALL( SCIPsetHeurInit(scip, heur, heurInitConflictdiving) );
515  SCIP_CALL( SCIPsetHeurExit(scip, heur, heurExitConflictdiving) );
516 
517  /* create a diveset (this will automatically install some additional parameters for the heuristic)*/
521  DIVESET_ISPUBLIC, DIVESET_DIVETYPES, divesetGetScoreConflictdiving, divesetAvailableConflictdiving) );
522 
523  SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/maxviol", "try to maximize the violation",
524  &heurdata->maxviol, TRUE, DEFAULT_MAXVIOL, NULL, NULL) );
525 
526  SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/likecoef",
527  "perform rounding like coefficient diving",
528  &heurdata->likecoefdiving, TRUE, DEFAULT_LIKECOEF, NULL, NULL) );
529 
530  SCIP_CALL( SCIPaddIntParam(scip, "heuristics/" HEUR_NAME "/minconflictlocks",
531  "minimal number of conflict locks per variable",
532  &heurdata->minconflictlocks, TRUE, DEFAULT_MINCONFLICTLOCKS, 0, INT_MAX, NULL, NULL) );
533 
534  SCIP_CALL( SCIPaddRealParam(scip, "heuristics/" HEUR_NAME "/lockweight",
535  "weight used in a convex combination of conflict and variable locks",
536  &heurdata->lockweight, TRUE, DEFAULT_LOCKWEIGHT, 0.0, 1.0, NULL, NULL) );
537 
538  return SCIP_OKAY;
539 }
static SCIP_DECL_HEURINIT(heurInitConflictdiving)
#define DEFAULT_MAXVIOL
public methods for SCIP parameter handling
int SCIPvarGetNLocksDownType(SCIP_VAR *var, SCIP_LOCKTYPE locktype)
Definition: var.c:3298
static SCIP_RETCODE getScore(SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_RANDNUMGEN *rng, SCIP_DIVETYPE divetype, SCIP_VAR *cand, SCIP_Real candsol, SCIP_Real candsfrac, SCIP_Real *score, SCIP_Bool *roundup)
#define DIVESET_ISPUBLIC
#define DEFAULT_ONLYLPBRANCHCANDS
public methods for memory management
int SCIPvarGetNLocksUpType(SCIP_VAR *var, SCIP_LOCKTYPE locktype)
Definition: var.c:3356
SCIP_RETCODE SCIPsetHeurExit(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEUREXIT((*heurexit)))
Definition: scip_heur.c:210
#define DEFAULT_MAXDIVEUBQUOTNOSOL
SCIP_DIVESET ** SCIPheurGetDivesets(SCIP_HEUR *heur)
Definition: heur.c:1648
SCIP_Bool SCIPvarIsBinary(SCIP_VAR *var)
Definition: var.c:17440
SCIP_Bool SCIPisFeasNegative(SCIP *scip, SCIP_Real val)
#define HEUR_MAXDEPTH
#define DEFAULT_MAXDIVEAVGQUOT
#define DEFAULT_RANDSEED
#define DEFAULT_BACKTRACK
#define TRUE
Definition: def.h:95
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
methods commonly used by primal heuristics
#define DEFAULT_LIKECOEF
struct SCIP_HeurData SCIP_HEURDATA
Definition: type_heur.h:76
public methods for problem variables
#define SCIPfreeBlockMemory(scip, ptr)
Definition: scip_mem.h:108
SCIP_RETCODE SCIPincludeHeurBasic(SCIP *scip, SCIP_HEUR **heur, const char *name, const char *desc, char dispchar, int priority, int freq, int freqofs, int maxdepth, SCIP_HEURTIMING timingmask, SCIP_Bool usessubscip, SCIP_DECL_HEUREXEC((*heurexec)), SCIP_HEURDATA *heurdata)
Definition: scip_heur.c:117
int SCIPrandomGetInt(SCIP_RANDNUMGEN *randnumgen, int minrandval, int maxrandval)
Definition: misc.c:10012
unsigned int SCIP_DIVETYPE
Definition: type_heur.h:63
SCIP_RETCODE SCIPcreateDiveset(SCIP *scip, SCIP_DIVESET **diveset, SCIP_HEUR *heur, const char *name, SCIP_Real minreldepth, SCIP_Real maxreldepth, SCIP_Real maxlpiterquot, SCIP_Real maxdiveubquot, SCIP_Real maxdiveavgquot, SCIP_Real maxdiveubquotnosol, SCIP_Real maxdiveavgquotnosol, SCIP_Real lpresolvedomchgquot, int lpsolvefreq, int maxlpiterofs, unsigned int initialseed, SCIP_Bool backtrack, SCIP_Bool onlylpbranchcands, SCIP_Bool ispublic, SCIP_Bool specificsos1score, SCIP_DECL_DIVESETGETSCORE((*divesetgetscore)), SCIP_DECL_DIVESETAVAILABLE((*divesetavailable)))
Definition: scip_heur.c:318
SCIP_Bool SCIPisEQ(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
void SCIPheurSetData(SCIP_HEUR *heur, SCIP_HEURDATA *heurdata)
Definition: heur.c:1371
#define SCIPallocBlockMemory(scip, ptr)
Definition: scip_mem.h:89
SCIP_RETCODE SCIPaddIntParam(SCIP *scip, const char *name, const char *desc, int *valueptr, SCIP_Bool isadvanced, int defaultvalue, int minvalue, int maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:83
SCIP_RETCODE SCIPperformGenericDivingAlgorithm(SCIP *scip, SCIP_DIVESET *diveset, SCIP_SOL *worksol, SCIP_HEUR *heur, SCIP_RESULT *result, SCIP_Bool nodeinfeasible, SCIP_Longint iterlim, SCIP_DIVECONTEXT divecontext)
Definition: heuristics.c:218
#define HEUR_TIMING
public methods for numerical tolerances
#define DEFAULT_LOCKWEIGHT
public methods for querying solving statistics
static SCIP_DECL_DIVESETGETSCORE(divesetGetScoreConflictdiving)
SCIP_HEUR * SCIPdivesetGetHeur(SCIP_DIVESET *diveset)
Definition: heur.c:414
const char * SCIPheurGetName(SCIP_HEUR *heur)
Definition: heur.c:1450
#define SCIPerrorMessage
Definition: pub_message.h:64
#define HEUR_FREQOFS
SCIP_RETCODE SCIPsetHeurFree(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURFREE((*heurfree)))
Definition: scip_heur.c:178
SCIP_Bool SCIPisLT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
#define HEUR_USESSUBSCIP
#define HEUR_PRIORITY
SCIP_SOL * sol
Definition: struct_heur.h:71
#define DEFAULT_LPRESOLVEDOMCHGQUOT
#define NULL
Definition: lpi_spx1.cpp:164
#define MAX_RAND
#define DEFAULT_MAXRELDEPTH
static SCIP_DECL_HEUREXEC(heurExecConflictdiving)
#define SCIP_CALL(x)
Definition: def.h:393
int SCIPheurGetNDivesets(SCIP_HEUR *heur)
Definition: heur.c:1658
#define SCIP_PROBINGSCORE_PENALTYRATIO
Definition: def.h:335
public methods for primal heuristic plugins and divesets
static SCIP_DECL_HEUREXIT(heurExitConflictdiving)
#define DEFAULT_MAXDIVEAVGQUOTNOSOL
public data structures and miscellaneous methods
SCIP_RETCODE SCIPincludeHeurConflictdiving(SCIP *scip)
#define SCIP_Bool
Definition: def.h:93
SCIP_RANDNUMGEN * SCIPdivesetGetRandnumgen(SCIP_DIVESET *diveset)
Definition: heur.c:718
#define DEFAULT_LPSOLVEFREQ
SCIP_RETCODE SCIPfreeSol(SCIP *scip, SCIP_SOL **sol)
Definition: scip_sol.c:985
SCIP_Longint SCIPgetNConflictConssFound(SCIP *scip)
#define HEUR_FREQ
SCIP_Real SCIPrandomGetReal(SCIP_RANDNUMGEN *randnumgen, SCIP_Real minrandval, SCIP_Real maxrandval)
Definition: misc.c:10034
#define DEFAULT_MAXDIVEUBQUOT
static SCIP_RETCODE getScoreLikeCoefdiving(SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_RANDNUMGEN *rng, SCIP_DIVETYPE divetype, SCIP_VAR *cand, SCIP_Real candsol, SCIP_Real candsfrac, SCIP_Real *score, SCIP_Bool *roundup)
#define DIVESET_DIVETYPES
SCIP_Bool SCIPisGT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
public methods for solutions
#define DEFAULT_MAXLPITEROFS
public methods for message output
SCIP_RETCODE SCIPsetHeurInit(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURINIT((*heurinit)))
Definition: scip_heur.c:194
#define HEUR_DESC
SCIP_Bool SCIPisFeasPositive(SCIP *scip, SCIP_Real val)
#define SCIP_Real
Definition: def.h:186
#define DEFAULT_MINRELDEPTH
LP diving heuristic that chooses fixings w.r.t. conflict locks.
#define SCIP_DIVETYPE_SOS1VARIABLE
Definition: type_heur.h:61
#define MIN_RAND
#define HEUR_NAME
static SCIP_DECL_HEURCOPY(heurCopyConflictdiving)
SCIP_Bool SCIPisZero(SCIP *scip, SCIP_Real val)
SCIP_RETCODE SCIPsetHeurCopy(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURCOPY((*heurcopy)))
Definition: scip_heur.c:162
public methods for primal heuristics
#define SCIP_DIVETYPE_INTEGRALITY
Definition: type_heur.h:60
SCIP_HEURDATA * SCIPheurGetData(SCIP_HEUR *heur)
Definition: heur.c:1361
#define divesetAvailableConflictdiving
#define DEFAULT_MAXLPITERQUOT
#define SCIPABORT()
Definition: def.h:365
static SCIP_DECL_HEURFREE(heurFreeConflictdiving)
SCIP_RETCODE SCIPaddRealParam(SCIP *scip, const char *name, const char *desc, SCIP_Real *valueptr, SCIP_Bool isadvanced, SCIP_Real defaultvalue, SCIP_Real minvalue, SCIP_Real maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:139
#define DEFAULT_MINCONFLICTLOCKS
SCIP_RETCODE SCIPaddBoolParam(SCIP *scip, const char *name, const char *desc, SCIP_Bool *valueptr, SCIP_Bool isadvanced, SCIP_Bool defaultvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:57
#define HEUR_DISPCHAR
SCIP_RETCODE SCIPcreateSol(SCIP *scip, SCIP_SOL **sol, SCIP_HEUR *heur)
Definition: scip_sol.c:328