Scippy

SCIP

Solving Constraint Integer Programs

sepa_rapidlearning.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 (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 sepa_rapidlearning.c
26  * @ingroup DEFPLUGINS_SEPA
27  * @brief rapidlearning separator
28  * @author Timo Berthold
29  * @author Jakob Witzig
30  */
31 
32 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
33 
34 #include <assert.h>
35 #ifndef NDEBUG
36 #include <string.h>
37 #endif
38 
40 #include "scip/scipdefplugins.h"
41 #include "scip/heuristics.h"
42 #include "scip/pub_var.h"
43 
44 #define SEPA_NAME "rapidlearning"
45 #define SEPA_DESC "rapid learning heuristic and separator"
46 #define SEPA_PRIORITY -1200000
47 #define SEPA_FREQ 5
48 #define SEPA_MAXBOUNDDIST 1.0
49 #define SEPA_USESSUBSCIP TRUE /**< does the separator use a secondary SCIP instance? */
50 #define SEPA_DELAY FALSE /**< should separation method be delayed, if other separators found cuts? */
51 
52 #define DEFAULT_APPLYCONFLICTS TRUE /**< should the found conflicts be applied in the original SCIP? */
53 #define DEFAULT_APPLYBDCHGS TRUE /**< should the found global bound deductions be applied in the original SCIP?
54  * apply only if conflicts and incumbent solution will be copied too
55  */
56 #define DEFAULT_APPLYINFERVALS TRUE /**< should the inference values be used as initialization in the original SCIP? */
57 #define DEFAULT_REDUCEDINFER FALSE /**< should the inference values only be used when rapid learning found other reductions? */
58 #define DEFAULT_APPLYPRIMALSOL TRUE /**< should the incumbent solution be copied to the original SCIP? */
59 #define DEFAULT_APPLYSOLVED TRUE /**< should a solved status be copied to the original SCIP? */
60 
61 #define DEFAULT_CHECKEXEC TRUE /**< check whether rapid learning should be executed */
62 #define DEFAULT_CHECKDEGANERACY TRUE /**< should local LP degeneracy be checked? */
63 #define DEFAULT_CHECKDUALBOUND FALSE /**< should the progress on the dual bound be checked? */
64 #define DEFAULT_CHECKLEAVES FALSE /**< should the ratio of leaves proven to be infeasible and exceeding the
65  * cutoff bound be checked? */
66 #define DEFAULT_CHECKOBJ FALSE /**< should the local objection function be checked? */
67 #define DEFAULT_CHECKNSOLS TRUE /**< should the number of solutions found so far be checked? */
68 #define DEFAULT_MINDEGENERACY 0.7 /**< minimal degeneracy threshold to allow local rapid learning */
69 #define DEFAULT_MININFLPRATIO 10.0 /**< minimal threshold of inf/obj leaves to allow local rapid learning */
70 #define DEFAULT_MINVARCONSRATIO 2.0 /**< minimal ratio of unfixed variables in relation to basis size to
71  * allow local rapid learning */
72 #define DEFAULT_NWAITINGNODES 100L /**< number of nodes that should be processed before rapid learning is
73  * executed locally based on the progress of the dualbound */
74 
75 #define DEFAULT_MAXNVARS 10000 /**< maximum problem size (variables) for which rapid learning will be called */
76 #define DEFAULT_MAXNCONSS 10000 /**< maximum problem size (constraints) for which rapid learning will be called */
77 #define DEFAULT_MAXCALLS 100 /**< maximum number of overall calls */
78 
79 #define DEFAULT_MINNODES 500 /**< minimum number of nodes considered in rapid learning run */
80 #define DEFAULT_MAXNODES 5000 /**< maximum number of nodes considered in rapid learning run */
81 
82 #define DEFAULT_CONTVARS FALSE /**< should rapid learning be applied when there are continuous variables? */
83 #define DEFAULT_CONTVARSQUOT 0.3 /**< maximal portion of continuous variables to apply rapid learning */
84 #define DEFAULT_LPITERQUOT 0.2 /**< maximal fraction of LP iterations compared to node LP iterations */
85 #define DEFAULT_COPYCUTS TRUE /**< should all active cuts from the cutpool of the
86  * original scip be copied to constraints of the subscip */
87 
88 
89 /*
90  * Data structures
91  */
92 
93 /** separator data */
94 struct SCIP_SepaData
95 {
96  SCIP_Real lpiterquot; /**< maximal fraction of LP iterations compared to node LP iterations */
97  SCIP_Real mindegeneracy; /**< minimal degeneracy threshold to allow local rapid learning */
98  SCIP_Real mininflpratio; /**< minimal threshold of inf/obj leaves to allow local rapid learning */
99  SCIP_Real minvarconsratio; /**< minimal ratio of unfixed variables in relation to basis size to
100  * allow local rapid learning */
101  int maxnvars; /**< maximum problem size (variables) for which rapid learning will be called */
102  int maxnconss; /**< maximum problem size (constraints) for which rapid learning will be called */
103  int maxcalls; /**< maximum number of overall calls */
104  int minnodes; /**< minimum number of nodes considered in rapid learning run */
105  int maxnodes; /**< maximum number of nodes considered in rapid learning run */
106  SCIP_Longint nwaitingnodes; /**< number of nodes that should be processed before rapid learning is executed locally
107  * based on the progress of the dualbound */
108  SCIP_Bool applybdchgs; /**< should the found global bound deductions be applied in the original SCIP? */
109  SCIP_Bool applyconflicts; /**< should the found conflicts be applied in the original SCIP? */
110  SCIP_Bool applyinfervals; /**< should the inference values be used as initialization in the original SCIP? */
111  SCIP_Bool applyprimalsol; /**< should the incumbent solution be copied to the original SCIP? */
112  SCIP_Bool applysolved; /**< should a solved status ba copied to the original SCIP? */
113  SCIP_Bool checkdegeneracy; /**< should local LP degeneracy be checked? */
114  SCIP_Bool checkdualbound; /**< should the progress on the dual bound be checked? */
115  SCIP_Bool checkleaves; /**< should the ratio of leaves proven to be infeasible and exceeding the
116  * cutoff bound be checked? */
117  SCIP_Bool checkexec; /**< check whether rapid learning should be executed */
118  SCIP_Bool checkobj; /**< should the (local) objective function be checked? */
119  SCIP_Bool checknsols; /**< should number if solutions found so far be checked? */
120  SCIP_Bool contvars; /**< should rapid learning be applied when there are continuous variables? */
121  SCIP_Real contvarsquot; /**< maximal portion of continuous variables to apply rapid learning */
122  SCIP_Bool copycuts; /**< should all active cuts from cutpool be copied to constraints in
123  * subproblem? */
124  SCIP_Bool reducedinfer; /**< should the inference values only be used when rapid learning found other reductions? */
125 };
126 
127 /*
128  * Callback methods of separator
129  */
130 
131 /** copy method for separator plugins (called when SCIP copies plugins) */
132 static
133 SCIP_DECL_SEPACOPY(sepaCopyRapidlearning)
134 { /*lint --e{715}*/
135  assert(scip != NULL);
136  assert(sepa != NULL);
137  assert(strcmp(SCIPsepaGetName(sepa), SEPA_NAME) == 0);
138 
139  /* call inclusion method of constraint handler */
141 
142  return SCIP_OKAY;
143 }
144 
145 /** destructor of separator to free user data (called when SCIP is exiting) */
146 static
147 SCIP_DECL_SEPAFREE(sepaFreeRapidlearning)
148 { /*lint --e{715}*/
149  SCIP_SEPADATA* sepadata;
150 
151  assert(sepa != NULL);
152  assert(strcmp(SCIPsepaGetName(sepa), SEPA_NAME) == 0);
153  assert(scip != NULL);
154 
155  /* free separator data */
156  sepadata = SCIPsepaGetData(sepa);
157  assert(sepadata != NULL);
158  SCIPfreeBlockMemory(scip, &sepadata);
159  SCIPsepaSetData(sepa, NULL);
160 
161  return SCIP_OKAY;
162 }
163 
164 
165 /** setup and solve sub-SCIP */
166 static
168  SCIP* scip, /**< SCIP data structure */
169  SCIP* subscip, /**< subSCIP data structure */
170  SCIP_SEPADATA* sepadata, /**< separator data */
171  int randseed, /**< global seed shift used in the sub-SCIP */
172  SCIP_Bool global, /**< should rapid learning run on the global problem? */
173  SCIP_RESULT* result /**< result pointer */
174  )
175 {
176  SCIP_VAR** vars; /* original problem's variables */
177  SCIP_VAR** subvars; /* subproblem's variables */
178  SCIP_HASHMAP* varmapfw; /* mapping of SCIP variables to sub-SCIP variables */
179  SCIP_HASHMAP* varmapbw = NULL; /* mapping of sub-SCIP variables to SCIP variables */
180 
181  SCIP_CONSHDLR** conshdlrs = NULL; /* array of constraint handler's that might that might obtain conflicts */
182  int* oldnconss = NULL; /* number of constraints without rapid learning conflicts */
183 
184  SCIP_Longint nodelimit; /* node limit for the subproblem */
185 
186  int nconshdlrs; /* size of conshdlr and oldnconss array */
187  int nvars; /* number of variables */
188  int nbinvars;
189  int nintvars;
190  int nimplvars;
191  int implstart;
192  int implend;
193  int restartnum; /* maximal number of conflicts that should be created */
194  int i; /* counter */
195 
196  SCIP_Bool success; /* was problem creation / copying constraint successful? */
197 
198  SCIP_Bool cutoff; /* detected infeasibility */
199  int nconflicts; /* statistic: number of conflicts applied */
200  int nbdchgs; /* statistic: number of bound changes applied */
201 
202  SCIP_Bool soladded = FALSE; /* statistic: was a new incumbent found? */
203  SCIP_Bool dualboundchg; /* statistic: was a new dual bound found? */
204  SCIP_Bool disabledualreductions; /* TRUE, if dual reductions in sub-SCIP are not valid for original SCIP,
205  * e.g., because a constraint could not be copied or a primal solution
206  * could not be copied back */
207  int initseed;
208  int seedshift;
209  SCIP_Bool valid;
210 
211 #ifdef SCIP_DEBUG
212  int n1startinfers = 0; /* statistic: number of one side infer values */
213  int n2startinfers = 0; /* statistic: number of both side infer values */
214 #endif
215 
216  SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, &nbinvars, &nintvars, &nimplvars, NULL) );
217 
218  /* initializing the subproblem */
219  SCIP_CALL( SCIPallocBufferArray(scip, &subvars, nvars) );
220  SCIP_CALL( SCIPhashmapCreate(&varmapfw, SCIPblkmem(subscip), nvars) );
221  valid = FALSE;
222 
223  /* copy the subproblem */
224  SCIP_CALL( SCIPcopyConsCompression(scip, subscip, varmapfw, NULL, "rapid", NULL, NULL, 0, global, FALSE, FALSE, TRUE, &valid) );
225 
226  if( sepadata->copycuts )
227  {
228  /* copies all active cuts from cutpool of sourcescip to linear constraints in targetscip */
229  SCIP_CALL( SCIPcopyCuts(scip, subscip, varmapfw, NULL, global, NULL) );
230  }
231 
232  /* fill subvars array in the order of the variables of the main SCIP */
233  for( i = 0; i < nvars; i++ )
234  {
235  subvars[i] = (SCIP_VAR*) SCIPhashmapGetImage(varmapfw, vars[i]);
236  }
237  SCIPhashmapFree(&varmapfw);
238 
239  /* change implicit integer variables to integer type */
240  implstart = nbinvars + nintvars;
241  implend = nbinvars + nintvars + nimplvars;
242  for( i = implstart; i < implend; i++ )
243  {
244  SCIP_Bool infeasible;
245 
246  if( subvars[i] == NULL )
247  continue;
248 
249  assert(SCIPvarGetType(subvars[i]) == SCIP_VARTYPE_IMPLINT);
250  SCIP_CALL( SCIPchgVarType(subscip, subvars[i], SCIP_VARTYPE_INTEGER, &infeasible) );
251  assert(!infeasible);
252  }
253 
254  /* This avoids dual presolving.
255  *
256  * If the copy is not valid, it should be a relaxation of the problem (constraints might have failed to be copied,
257  * but no variables should be missing because we stop earlier anyway if pricers are present).
258  * By disabling dual presolving, conflicts and bound changes found in a relaxation are still valid for the original problem.
259  */
260  if( ! valid )
261  {
262  SCIP_CALL( SCIPsetBoolParam(subscip, "misc/allowweakdualreds", FALSE) );
263  SCIP_CALL( SCIPsetBoolParam(subscip, "misc/allowstrongdualreds", FALSE) );
264  }
265 
266  SCIPdebugMsg(scip, "Copying SCIP was%s valid.\n", valid ? "" : " not");
267 
268  /* mimic an FD solver: DFS, no LP solving, 1-FUIP instead of all-FUIP, ... */
269  if( SCIPisParamFixed(subscip, "lp/solvefreq") )
270  {
271  SCIPwarningMessage(scip, "unfixing parameter lp/solvefreq in subscip of rapidlearning\n");
272  SCIP_CALL( SCIPunfixParam(subscip, "lp/solvefreq") );
273  }
274  if( SCIPisParamFixed(subscip, "nodeselection/dfs/stdpriority") )
275  {
276  SCIPwarningMessage(scip, "unfixing parameter nodeselection/dfs/stdpriority in subscip of rapidlearning\n");
277  SCIP_CALL( SCIPunfixParam(subscip, "nodeselection/dfs/stdpriority") );
278  }
280 
281  /* turn off pseudo objective propagation */
282  if( !SCIPisParamFixed(subscip, "propagating/pseudoobj/freq") )
283  {
284  SCIP_CALL( SCIPsetIntParam(subscip, "propagating/pseudoobj/freq", -1) );
285  }
286 
287  /* use classic inference branching */
288  if( !SCIPisParamFixed(subscip, "branching/inference/useweightedsum") )
289  {
290  SCIP_CALL( SCIPsetBoolParam(subscip, "branching/inference/useweightedsum", FALSE) );
291  }
292 
293  /* only create short conflicts */
294  if( !SCIPisParamFixed(subscip, "conflict/maxvarsfac") )
295  {
296  SCIP_CALL( SCIPsetRealParam(subscip, "conflict/maxvarsfac", 0.05) );
297  }
298 
299  /* set node limit for the subproblem based on the number of LP iterations per node,
300  * which are a determistic measure for the node processing time.
301  *
302  * Note: We scale by number of LPs + 1 because the counter is increased after solving the LP.
303  */
304  nodelimit = SCIPgetNLPIterations(scip) / (SCIPgetNLPs(scip) + 1);
305  nodelimit = MAX(sepadata->minnodes, nodelimit);
306  nodelimit = MIN(sepadata->maxnodes, nodelimit);
307 
308  /* change global random seed */
309  assert(randseed >= 0);
310  SCIP_CALL( SCIPgetIntParam(scip, "randomization/randomseedshift", &seedshift) );
311 
312  initseed = ((randseed + seedshift) % INT_MAX);
313  SCIP_CALL( SCIPsetIntParam(subscip, "randomization/randomseedshift", initseed) );
314 
315  restartnum = 1000;
316 
317  #ifdef SCIP_DEBUG
318  /* for debugging, enable full output */
319  SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 5) );
320  SCIP_CALL( SCIPsetIntParam(subscip, "display/freq", -1) );
321  #else
322  /* disable statistic timing inside sub SCIP and output to console */
323  SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) );
324  SCIP_CALL( SCIPsetBoolParam(subscip, "timing/statistictiming", FALSE) );
325  #endif
326 
327  /* set limits for the subproblem */
328  SCIP_CALL( SCIPcopyLimits(scip, subscip) );
329  SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nodelimit/5) );
330  SCIP_CALL( SCIPsetIntParam(subscip, "limits/restarts", 0) );
331  SCIP_CALL( SCIPsetIntParam(subscip, "conflict/restartnum", restartnum) );
332 
333  /* forbid recursive call of heuristics and separators solving subMIPs */
334  SCIP_CALL( SCIPsetSubscipsOff(subscip, TRUE) );
335 
336  /* disable cutting plane separation */
338 
339  /* disable expensive presolving */
341 
342  /* do not abort subproblem on CTRL-C */
343  SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) );
344 
345  /* add an objective cutoff */
346  SCIP_CALL( SCIPsetObjlimit(subscip, SCIPgetUpperbound(scip)) );
347 
348  /* create the variable mapping hash map */
349  SCIP_CALL( SCIPhashmapCreate(&varmapbw, SCIPblkmem(scip), nvars) );
350 
351  /* store reversing mapping of variables */
352  SCIP_CALL( SCIPtransformProb(subscip) );
353  for( i = 0; i < nvars; ++i)
354  {
355  if( subvars[i] != NULL )
356  {
357  SCIP_CALL( SCIPhashmapInsert(varmapbw, SCIPvarGetTransVar(subvars[i]), vars[i]) );
358  }
359  }
360 
361  /* allocate memory for constraints storage. Each constraint that will be created from now on will be a conflict.
362  * Therefore, we need to remember oldnconss to get the conflicts from the FD search.
363  */
364  nconshdlrs = 4;
365  SCIP_CALL( SCIPallocBufferArray(scip, &conshdlrs, nconshdlrs) );
366  SCIP_CALL( SCIPallocBufferArray(scip, &oldnconss, nconshdlrs) );
367 
368  /* store number of constraints before rapid learning search */
369  conshdlrs[0] = SCIPfindConshdlr(subscip, "setppc");
370  conshdlrs[1] = SCIPfindConshdlr(subscip, "logicor");
371  conshdlrs[2] = SCIPfindConshdlr(subscip, "linear");
372  conshdlrs[3] = SCIPfindConshdlr(subscip, "bounddisjunction");
373 
374  /* redundant constraints might be eliminated in presolving */
375  SCIP_CALL( SCIPpresolve(subscip) );
376 
377  for( i = 0; i < nconshdlrs; ++i)
378  {
379  if( conshdlrs[i] != NULL )
380  oldnconss[i] = SCIPconshdlrGetNConss(conshdlrs[i]);
381  }
382 
383  /* solve the subproblem, abort after errors in debug mode */
384  SCIP_CALL_ABORT( SCIPsolve(subscip) );
385 
386  /* if problem was already solved do not increase limits to run again */
387  if( SCIPgetStage(subscip) == SCIP_STAGE_SOLVED )
388  {
389  SCIPdebugMsg(scip, "Subscip was completely solved, status %d.\n", SCIPgetStatus(subscip));
390  }
391  /* abort solving, if limit of applied conflicts is reached */
392  else if( SCIPgetNConflictConssApplied(subscip) >= restartnum )
393  {
394  SCIPdebugMsg(scip, "finish after %" SCIP_LONGINT_FORMAT " successful conflict calls.\n", SCIPgetNConflictConssApplied(subscip));
395  }
396  /* if the first 20% of the solution process were successful, proceed */
397  else if( (sepadata->applyprimalsol && SCIPgetNSols(subscip) > 0 && SCIPisFeasLT(scip, SCIPgetUpperbound(subscip), SCIPgetUpperbound(scip) ) )
398  || (sepadata->applybdchgs && SCIPgetNRootboundChgs(subscip) > 0 )
399  || (sepadata->applyconflicts && SCIPgetNConflictConssApplied(subscip) > 0) )
400  {
401  SCIPdebugMsg(scip, "proceed solving after the first 20%% of the solution process, since:\n");
402 
403  if( SCIPgetNSols(subscip) > 0 && SCIPisFeasLE(scip, SCIPgetUpperbound(subscip), SCIPgetUpperbound(scip) ) )
404  {
405  SCIPdebugMsg(scip, " - there was a better solution (%f < %f)\n",SCIPgetUpperbound(subscip), SCIPgetUpperbound(scip));
406  }
407  if( SCIPgetNRootboundChgs(subscip) > 0 )
408  {
409  SCIPdebugMsg(scip, " - there were %d changed variables bounds\n", SCIPgetNRootboundChgs(subscip) );
410  }
411  if( SCIPgetNConflictConssFound(subscip) > 0 )
412  {
413  SCIPdebugMsg(scip, " - there were %" SCIP_LONGINT_FORMAT " conflict constraints created\n", SCIPgetNConflictConssApplied(subscip));
414  }
415 
416  /* set node limit to 100% */
417  SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nodelimit) );
418 
419  /* solve the subproblem, abort after errors in debug mode */
420  SCIP_CALL_ABORT( SCIPsolve(subscip) );
421  }
422  else
423  {
424  SCIPdebugMsg(scip, "do not proceed solving after the first 20%% of the solution process.\n");
425  }
426 
427  #ifdef SCIP_DEBUG
428  SCIP_CALL( SCIPprintStatistics(subscip, NULL) );
429  #endif
430 
431  if( SCIPallowStrongDualReds(scip) )
432  disabledualreductions = FALSE;
433  else
434  disabledualreductions = TRUE;
435 
436  /* check, whether a solution was found */
437  if( sepadata->applyprimalsol && SCIPgetNSols(subscip) > 0 )
438  {
439  SCIP_SOL** subsols;
440  int nsubsols;
441 
442  /* check, whether a solution was found;
443  * due to numerics, it might happen that not all solutions are feasible -> try all solutions until was declared to be feasible
444  */
445  nsubsols = SCIPgetNSols(subscip);
446  subsols = SCIPgetSols(subscip);
447  soladded = FALSE;
448 
449  /* try adding solution from subSCIP to SCIP, until finding one that is accepted */
450  for( i = 0; i < nsubsols && !soladded; ++i )
451  {
452  SCIP_SOL* newsol;
453 
454  SCIP_CALL( SCIPtranslateSubSol(scip, subscip, subsols[i], NULL, subvars, &newsol) );
455  SCIP_CALL( SCIPtrySolFree(scip, &newsol, FALSE, FALSE, TRUE, TRUE, TRUE, &soladded) );
456  }
457  if( !soladded || !SCIPisEQ(scip, SCIPgetSolOrigObj(subscip, subsols[i-1]), SCIPgetSolOrigObj(subscip, subsols[0])) )
458  disabledualreductions = TRUE;
459  }
460 
461  /* if the sub problem was solved completely, we update the dual bound */
462  dualboundchg = FALSE;
463  if( sepadata->applysolved && !disabledualreductions
465  {
466  /* we need to multiply the dualbound with the scaling factor and add the offset,
467  * because this information has been disregarded in the sub-SCIP
468  */
469  SCIPdebugMsg(scip, "Update old dualbound %g to new dualbound %g.\n",
470  SCIPgetDualbound(scip), SCIPretransformObj(scip, SCIPgetDualbound(subscip)));
471 
473  dualboundchg = TRUE;
474  }
475 
476  /* check, whether conflicts were created */
477  nconflicts = 0;
478  if( sepadata->applyconflicts && !disabledualreductions && SCIPgetNConflictConssApplied(subscip) > 0 )
479  {
480  SCIP_HASHMAP* consmap;
481  int hashtablesize;
482  int nmaxconfs;
483 
484  assert(SCIPgetNConflictConssApplied(subscip) < (SCIP_Longint) INT_MAX);
485  hashtablesize = (int) SCIPgetNConflictConssApplied(subscip);
486  assert(hashtablesize < INT_MAX/5);
487 
488  /* create the variable mapping hash map */
489  SCIP_CALL( SCIPhashmapCreate(&consmap, SCIPblkmem(scip), hashtablesize) );
490 
491  SCIP_CALL( SCIPgetIntParam(scip, "conflict/maxconss", &nmaxconfs) );
492  if( global )
493  nmaxconfs *= 20;
494 
495  /* loop over all constraint handlers that might contain conflict constraints
496  * @todo select promising constraints and not greedy
497  */
498  for( i = 0; i < nconshdlrs && nconflicts < nmaxconfs; ++i)
499  {
500  /* copy constraints that have been created in FD run */
501  if( conshdlrs[i] != NULL && SCIPconshdlrGetNConss(conshdlrs[i]) > oldnconss[i] )
502  {
503  SCIP_CONS** conss;
504  int c;
505  int nconss;
506 
507  nconss = SCIPconshdlrGetNConss(conshdlrs[i]);
508  conss = SCIPconshdlrGetConss(conshdlrs[i]);
509 
510  /* loop over all constraints that have been added in sub-SCIP run, these are the conflicts */
511  for( c = oldnconss[i]; c < nconss && nconflicts < nmaxconfs; ++c)
512  {
513  SCIP_CONS* cons;
514  SCIP_CONS* conscopy;
515 
516  cons = conss[c];
517  assert(cons != NULL);
518 
519  success = FALSE;
520 
521  /* @todo assert that flags are as they should be for conflicts */
522  SCIP_CALL( SCIPgetConsCopy(subscip, scip, cons, &conscopy, conshdlrs[i], varmapbw, consmap, NULL,
524  SCIPconsIsPropagated(cons), !global, FALSE, SCIPconsIsDynamic(cons),
525  SCIPconsIsRemovable(cons), FALSE, TRUE, &success) );
526 
527  if( success )
528  {
529  nconflicts++;
530 
531  SCIP_CALL( SCIPaddConflict(scip, global ? NULL : SCIPgetCurrentNode(scip), conscopy, NULL,
533  }
534  else
535  {
536  SCIPdebugMsg(scip, "failed to copy conflict constraint %s back to original SCIP\n", SCIPconsGetName(cons));
537  }
538  }
539  }
540  }
541  SCIPhashmapFree(&consmap);
542  }
543 
544  /* check, whether tighter (global) bounds were detected */
545  cutoff = FALSE;
546  nbdchgs = 0;
547  if( sepadata->applybdchgs && !disabledualreductions )
548  {
549  for( i = 0; i < nvars; ++i )
550  {
551  SCIP_Bool tightened;
552 
553  if( subvars[i] == NULL )
554  continue;
555 
556  assert(SCIPisLE(scip, SCIPvarGetLbGlobal(vars[i]), SCIPvarGetLbGlobal(subvars[i])));
557  assert(SCIPisLE(scip, SCIPvarGetLbGlobal(subvars[i]), SCIPvarGetUbGlobal(subvars[i])));
558  assert(SCIPisLE(scip, SCIPvarGetUbGlobal(subvars[i]), SCIPvarGetUbGlobal(vars[i])));
559 
560  /* update the bounds of the original SCIP, if a better bound was proven in the sub-SCIP */
561  if( global )
562  {
563 #ifndef NDEBUG
564  assert(SCIPgetEffectiveRootDepth(scip) == SCIPgetDepth(scip));
565 #else
566  if( SCIPgetEffectiveRootDepth(scip) < SCIPgetDepth(scip) )
567  return SCIP_INVALIDCALL;
568 #endif
569  tightened = FALSE;
570 
571  SCIP_CALL( SCIPtightenVarUbGlobal(scip, vars[i], SCIPvarGetUbGlobal(subvars[i]), FALSE, &cutoff, &tightened) );
572 
573  if( cutoff )
574  break;
575 
576  if( tightened )
577  nbdchgs++;
578 
579  tightened = FALSE;
580 
581  SCIP_CALL( SCIPtightenVarLbGlobal(scip, vars[i], SCIPvarGetLbGlobal(subvars[i]), FALSE, &cutoff, &tightened) );
582 
583  if( cutoff )
584  break;
585 
586  if( tightened )
587  nbdchgs++;
588  }
589  else
590  {
591  tightened = FALSE;
592 
593  SCIP_CALL( SCIPtightenVarUb(scip, vars[i], SCIPvarGetUbGlobal(subvars[i]), FALSE, &cutoff, &tightened) );
594 
595  if( cutoff )
596  break;
597 
598  if( tightened )
599  nbdchgs++;
600 
601  tightened = FALSE;
602 
603  SCIP_CALL( SCIPtightenVarLb(scip, vars[i], SCIPvarGetLbGlobal(subvars[i]), FALSE, &cutoff, &tightened) );
604 
605  if( cutoff )
606  break;
607 
608  if( tightened )
609  nbdchgs++;
610  }
611  }
612  }
613 
614  /* install start values for inference branching */
615  /* @todo use different nbranching counters for pseudo cost and inference values and update inference values in the tree */
616  if( sepadata->applyinfervals && global && (!sepadata->reducedinfer || soladded || nbdchgs + nconflicts > 0) )
617  {
618  for( i = 0; i < nvars; ++i )
619  {
620  SCIP_Real downinfer;
621  SCIP_Real upinfer;
622  SCIP_Real downvsids;
623  SCIP_Real upvsids;
624  SCIP_Real downconflen;
625  SCIP_Real upconflen;
626 
627  if( subvars[i] == NULL )
628  continue;
629 
630  /* copy downwards branching statistics */
631  downvsids = SCIPgetVarVSIDS(subscip, subvars[i], SCIP_BRANCHDIR_DOWNWARDS);
632  downconflen = SCIPgetVarAvgConflictlength(subscip, subvars[i], SCIP_BRANCHDIR_DOWNWARDS);
633  downinfer = SCIPgetVarAvgInferences(subscip, subvars[i], SCIP_BRANCHDIR_DOWNWARDS);
634 
635  /* copy upwards branching statistics */
636  upvsids = SCIPgetVarVSIDS(subscip, subvars[i], SCIP_BRANCHDIR_UPWARDS);
637  upconflen = SCIPgetVarAvgConflictlength(subscip, subvars[i], SCIP_BRANCHDIR_UPWARDS);
638  upinfer = SCIPgetVarAvgInferences(subscip, subvars[i], SCIP_BRANCHDIR_UPWARDS);
639 
640 #ifdef SCIP_DEBUG
641  /* memorize statistics */
642  if( downinfer+downconflen+downvsids > 0.0 || upinfer+upconflen+upvsids != 0 )
643  n1startinfers++;
644 
645  if( downinfer+downconflen+downvsids > 0.0 && upinfer+upconflen+upvsids != 0 )
646  n2startinfers++;
647 #endif
648 
649  SCIP_CALL( SCIPinitVarBranchStats(scip, vars[i], 0.0, 0.0, downvsids, upvsids, downconflen, upconflen, downinfer, upinfer, 0.0, 0.0) );
650  }
651  }
652 
653 #ifdef SCIP_DEBUG
654  if( cutoff )
655  {
656  SCIPdebugMsg(scip, "Rapidlearning detected %s infeasibility.\n", global ? "global" : "local");
657  }
658 
659  SCIPdebugMsg(scip, "Rapidlearning added %d %s conflicts, changed %d bounds, %s primal solution, %s dual bound improvement.\n",
660  nconflicts, global ? "global" : "local", nbdchgs, soladded ? "found" : "no", dualboundchg ? "found" : "no");
661 
662  SCIPdebugMsg(scip, "YYY Infervalues initialized on one side: %5.2f %% of variables, %5.2f %% on both sides\n",
663  100.0 * n1startinfers/(SCIP_Real)nvars, 100.0 * n2startinfers/(SCIP_Real)nvars);
664 #endif
665 
666  /* change result pointer */
667  if( cutoff )
668  *result = SCIP_CUTOFF;
669  else if( nconflicts > 0 || dualboundchg )
670  *result = SCIP_CONSADDED;
671  else if( nbdchgs > 0 )
672  *result = SCIP_REDUCEDDOM;
673 
674  /* free local data */
675  assert(oldnconss != NULL);
676  assert(conshdlrs != NULL);
677  assert(varmapbw != NULL);
678  SCIPfreeBufferArray(scip, &oldnconss);
679  SCIPfreeBufferArray(scip, &conshdlrs);
680  SCIPhashmapFree(&varmapbw);
681 
682  /* free subproblem */
683  SCIPfreeBufferArray(scip, &subvars);
684 
685  return SCIP_OKAY;
686 }
687 
688 /** returns whether rapid learning is allowed to run locally */
689 static
691  SCIP* scip, /**< SCIP data structure */
692  SCIP_SEPADATA* sepadata, /**< separator's private data */
693  SCIP_Bool* run /**< pointer to store whether rapid learning is allowed to run */
694  )
695 {
696  assert(scip != NULL);
697  assert(sepadata != NULL);
698 
699  *run = FALSE;
700 
701  /* return TRUE if local exec should not be checked */
702  if( !sepadata->checkexec )
703  {
704  *run = TRUE;
705  }
706 
707  /* problem has zero objective function, i.e., it is a pure feasibility problem */
708  if( !(*run) && sepadata->checkobj && SCIPgetNObjVars(scip) == 0 )
709  {
710  SCIPdebugMsg(scip, "-> allow local rapid learning due to global zero objective\n");
711 
712  *run = TRUE;
713  }
714 
715  /* check whether a solution was found */
716  if( !(*run) && sepadata->checknsols && SCIPgetNSolsFound(scip) == 0 )
717  {
718  SCIPdebugMsg(scip, "-> allow local rapid learning due to no solution found so far\n");
719 
720  *run = TRUE;
721  }
722 
723  /* check whether the dual bound has not changed since the root node */
724  if( !(*run) && sepadata->checkdualbound && sepadata->nwaitingnodes < SCIPgetNNodes(scip) )
725  {
726  SCIP_Real rootdualbound;
727  SCIP_Real locdualbound;
728 
729  rootdualbound = SCIPgetLowerboundRoot(scip);
730  locdualbound = SCIPgetLocalLowerbound(scip);
731 
732  if( SCIPisEQ(scip, rootdualbound, locdualbound) )
733  {
734  SCIPdebugMsg(scip, "-> allow local rapid learning due to equal dualbound\n");
735 
736  *run = TRUE;
737  }
738  }
739 
740  /* check leaf nodes */
741  if( !(*run) && sepadata->checkleaves )
742  {
743  SCIP_Real ratio = (SCIPgetNInfeasibleLeaves(scip) + 1.0) / (SCIPgetNObjlimLeaves(scip) + 1.0);
744 
745  if( SCIPisLE(scip, sepadata->mininflpratio, ratio) )
746  {
747  SCIPdebugMsg(scip, "-> allow local rapid learning due to inf/obj leaves ratio\n");
748 
749  *run = TRUE;
750  }
751  }
752 
753  /* check whether all undecided integer variables have zero objective coefficient */
754  if( !(*run) && sepadata->checkobj )
755  {
756  SCIP_Bool allzero;
757  SCIP_VAR** vars;
758  int ndiscvars;
759  int i;
760 
761  allzero = TRUE;
762  vars = SCIPgetVars(scip);
763  ndiscvars = SCIPgetNBinVars(scip) + SCIPgetNIntVars(scip) + SCIPgetNImplVars(scip);
764 
765  for( i = 0; i < ndiscvars; i++ )
766  {
767  assert(SCIPvarIsIntegral(vars[i]));
768 
769  /* skip locally fixed variables */
770  if( SCIPisEQ(scip, SCIPvarGetLbLocal(vars[i]), SCIPvarGetUbLocal(vars[i])) )
771  continue;
772 
773  if( !SCIPisZero(scip, SCIPvarGetObj(vars[i])) )
774  {
775  allzero = FALSE;
776  break;
777  }
778  }
779 
780  if( allzero )
781  {
782  SCIPdebugMsg(scip, "-> allow local rapid learning due to local zero objective\n");
783 
784  *run = TRUE;
785  }
786  }
787 
788  /* check degeneracy */
789  if( !(*run) && sepadata->checkdegeneracy )
790  {
791  SCIP_Real degeneracy;
792  SCIP_Real varconsratio;
793 
794  SCIP_CALL( SCIPgetLPDualDegeneracy(scip, &degeneracy, &varconsratio) );
795 
796  SCIPdebugMsg(scip, "degeneracy: %.2f ratio: %.2f\n", degeneracy, varconsratio);
797 
798  if( degeneracy >= sepadata->mindegeneracy || varconsratio >= sepadata->minvarconsratio )
799  {
800  SCIPdebugMsg(scip, "-> allow local rapid learning due to degeneracy\n");
801 
802  *run = TRUE;
803  }
804  }
805 
806  return SCIP_OKAY;
807 }
808 
809 /** LP solution separation method of separator */
810 static
811 SCIP_DECL_SEPAEXECLP(sepaExeclpRapidlearning)
812 {/*lint --e{715}*/
813  SCIP_VAR** vars;
814  SCIP* subscip;
815  SCIP_SEPADATA* sepadata;
816  SCIP_Bool global;
818  SCIP_Bool success;
819  SCIP_RETCODE retcode;
820  int ndiscvars;
821  int i;
822 
823  assert(sepa != NULL);
824  assert(scip != NULL);
825  assert(result != NULL);
826 
827  *result = SCIP_DIDNOTRUN;
828 
829  ndiscvars = SCIPgetNBinVars(scip) + SCIPgetNIntVars(scip) + SCIPgetNImplVars(scip);
830 
831  /* only run when still not fixed binary variables exists */
832  if( ndiscvars == 0 )
833  return SCIP_OKAY;
834 
835  /* get separator's data */
836  sepadata = SCIPsepaGetData(sepa);
837  assert(sepadata != NULL);
838 
839  /* call separator at most maxcalls times */
840  if( SCIPsepaGetNCalls(sepa) >= sepadata->maxcalls )
841  return SCIP_OKAY;
842 
843  /* only run for integer programs */
844  if( !sepadata->contvars && ndiscvars != SCIPgetNVars(scip) )
845  return SCIP_OKAY;
846 
847  /* only run if there are few enough continuous variables */
848  if( sepadata->contvars && SCIPgetNContVars(scip) > sepadata->contvarsquot * SCIPgetNVars(scip) )
849  return SCIP_OKAY;
850 
851  /* do not run if pricers are present */
852  if( SCIPgetNActivePricers(scip) > 0 )
853  return SCIP_OKAY;
854 
855  /* if the separator should be exclusive to the root node, this prevents multiple calls due to restarts */
856  if( SCIPsepaGetFreq(sepa) == 0 && SCIPsepaGetNCalls(sepa) > 0 )
857  return SCIP_OKAY;
858 
859  /* call separator at most once per node */
860  if( SCIPsepaGetNCallsAtNode(sepa) > 0 )
861  return SCIP_OKAY;
862 
863  /* the information deduced from rapid learning is globally valid only if we are at the root node; thus we can't use
864  * the depth argument of the callback
865  */
866  global = (SCIPgetDepth(scip) <= SCIPgetEffectiveRootDepth(scip));
867 
868  /* check if rapid learning should be applied locally */
869  SCIP_CALL( checkExec(scip, sepadata, &run) );
870 
871  /* @todo check whether we want to run at the root node again, e.g., inf/obj ratio is large enough */
872  if( !run )
873  return SCIP_OKAY;
874 
875  /* do not call rapid learning, if the problem is too big */
876  if( SCIPgetNVars(scip) > sepadata->maxnvars || SCIPgetNConss(scip) > sepadata->maxnconss )
877  return SCIP_OKAY;
878 
879  if( SCIPisStopped(scip) )
880  return SCIP_OKAY;
881 
882  /* check whether there is enough time and memory left */
883  SCIP_CALL( SCIPcheckCopyLimits(scip, &success) );
884 
885  if( !success)
886  return SCIP_OKAY;
887 
888  /* skip rapid learning when the sub-SCIP would contain an integer variable with an infinite bound in direction of the
889  * objective function; this might lead to very bad branching decisions when enforcing a pseudo solution (#1439)
890  */
891  vars = SCIPgetVars(scip);
892  for( i = SCIPgetNBinVars(scip); i < ndiscvars; i++ )
893  {
894  SCIP_Real lb = SCIPvarGetLbLocal(vars[i]);
895  SCIP_Real ub = SCIPvarGetUbLocal(vars[i]);
896  SCIP_Real obj = SCIPvarGetObj(vars[i]);
897 
898  if( (SCIPisNegative(scip, obj) && SCIPisInfinity(scip, ub))
899  || (SCIPisPositive(scip, obj) && SCIPisInfinity(scip, -lb)) )
900  {
901  SCIPdebugMsg(scip, "unbounded integer variable %s (in [%g,%g]) with objective %g -> skip rapid learning\n",
902  SCIPvarGetName(vars[i]), lb, ub, obj);
903  return SCIP_OKAY;
904  }
905  }
906 
907  *result = SCIP_DIDNOTFIND;
908 
909  SCIP_CALL( SCIPcreate(&subscip) );
910 
911  retcode = setupAndSolveSubscipRapidlearning(scip, subscip, sepadata, (int)SCIPsepaGetNCalls(sepa)+1, global, result);
912 
913  SCIP_CALL( SCIPfree(&subscip) );
914 
915  return retcode;
916 }
917 
918 
919 /*
920  * separator specific interface methods
921  */
922 
923 /** creates the rapidlearning separator and includes it in SCIP */
925  SCIP* scip /**< SCIP data structure */
926  )
927 {
928  SCIP_SEPADATA* sepadata;
929  SCIP_SEPA* sepa;
931  /* create rapidlearning separator data */
932  SCIP_CALL( SCIPallocBlockMemory(scip, &sepadata) );
933 
934  /* include separator */
937  sepaExeclpRapidlearning, NULL,
938  sepadata) );
939 
940  assert(sepa != NULL);
941 
942  /* set non-NULL pointers to callback methods */
943  SCIP_CALL( SCIPsetSepaCopy(scip, sepa, sepaCopyRapidlearning) );
944  SCIP_CALL( SCIPsetSepaFree(scip, sepa, sepaFreeRapidlearning) );
945 
946  /* add rapidlearning separator parameters */
947  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/applyconflicts",
948  "should the found conflicts be applied in the original SCIP?",
949  &sepadata->applyconflicts, TRUE, DEFAULT_APPLYCONFLICTS, NULL, NULL) );
950 
951  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/applybdchgs",
952  "should the found global bound deductions be applied in the original SCIP?",
953  &sepadata->applybdchgs, TRUE, DEFAULT_APPLYBDCHGS, NULL, NULL) );
954 
955  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/applyinfervals",
956  "should the inference values be used as initialization in the original SCIP?",
957  &sepadata->applyinfervals, TRUE, DEFAULT_APPLYINFERVALS, NULL, NULL) );
958 
959  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/reducedinfer",
960  "should the inference values only be used when " SEPA_NAME " found other reductions?",
961  &sepadata->reducedinfer, TRUE, DEFAULT_REDUCEDINFER, NULL, NULL) );
962 
963  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/applyprimalsol",
964  "should the incumbent solution be copied to the original SCIP?",
965  &sepadata->applyprimalsol, TRUE, DEFAULT_APPLYPRIMALSOL, NULL, NULL) );
966 
967  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/applysolved",
968  "should a solved status be copied to the original SCIP?",
969  &sepadata->applysolved, TRUE, DEFAULT_APPLYSOLVED, NULL, NULL) );
970 
971  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/checkdegeneracy",
972  "should local LP degeneracy be checked?",
973  &sepadata->checkdegeneracy, TRUE, DEFAULT_CHECKDEGANERACY, NULL, NULL) );
974 
975  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/checkdualbound",
976  "should the progress on the dual bound be checked?",
977  &sepadata->checkdualbound, TRUE, DEFAULT_CHECKDUALBOUND, NULL, NULL) );
978 
979  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/checkleaves",
980  "should the ratio of leaves proven to be infeasible and exceeding the cutoff bound be checked?",
981  &sepadata->checkleaves, TRUE, DEFAULT_CHECKLEAVES, NULL, NULL) );
982 
983  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/checkexec",
984  "check whether rapid learning should be executed",
985  &sepadata->checkexec, TRUE, DEFAULT_CHECKEXEC, NULL, NULL) );
986 
987  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/checkobj",
988  "should the (local) objective function be checked?",
989  &sepadata->checkobj, TRUE, DEFAULT_CHECKOBJ, NULL, NULL) );
990 
991  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/checknsols",
992  "should the number of solutions found so far be checked?",
993  &sepadata->checknsols, TRUE, DEFAULT_CHECKNSOLS, NULL, NULL) );
994 
995  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/contvars",
996  "should rapid learning be applied when there are continuous variables?",
997  &sepadata->contvars, TRUE, DEFAULT_CONTVARS, NULL, NULL) );
998 
999  SCIP_CALL( SCIPaddRealParam(scip, "separating/" SEPA_NAME "/contvarsquot",
1000  "maximal portion of continuous variables to apply rapid learning",
1001  &sepadata->contvarsquot, TRUE, DEFAULT_CONTVARSQUOT, 0.0, 1.0, NULL, NULL) );
1002 
1003  SCIP_CALL( SCIPaddRealParam(scip, "separating/" SEPA_NAME "/lpiterquot",
1004  "maximal fraction of LP iterations compared to node LP iterations",
1005  &sepadata->lpiterquot, TRUE, DEFAULT_LPITERQUOT, 0.0, SCIP_REAL_MAX, NULL, NULL) );
1006 
1007  SCIP_CALL( SCIPaddRealParam(scip, "separating/" SEPA_NAME "/mindegeneracy",
1008  "minimal degeneracy threshold to allow local rapid learning",
1009  &sepadata->mindegeneracy, TRUE, DEFAULT_MINDEGENERACY, 0.0, 1.0, NULL, NULL) );
1010 
1011  SCIP_CALL( SCIPaddRealParam(scip, "separating/" SEPA_NAME "/mininflpratio",
1012  "minimal threshold of inf/obj leaves to allow local rapid learning",
1013  &sepadata->mininflpratio, TRUE, DEFAULT_MININFLPRATIO, 0.0, SCIP_REAL_MAX, NULL, NULL) );
1014 
1015  SCIP_CALL( SCIPaddRealParam(scip, "separating/" SEPA_NAME "/minvarconsratio",
1016  "minimal ratio of unfixed variables in relation to basis size to allow local rapid learning",
1017  &sepadata->minvarconsratio, TRUE, DEFAULT_MINVARCONSRATIO, 1.0, SCIP_REAL_MAX, NULL, NULL) );
1018 
1019  SCIP_CALL( SCIPaddIntParam(scip, "separating/" SEPA_NAME "/maxnvars",
1020  "maximum problem size (variables) for which rapid learning will be called",
1021  &sepadata->maxnvars, TRUE, DEFAULT_MAXNVARS, 0, INT_MAX, NULL, NULL) );
1022 
1023  SCIP_CALL( SCIPaddIntParam(scip, "separating/" SEPA_NAME "/maxnconss",
1024  "maximum problem size (constraints) for which rapid learning will be called",
1025  &sepadata->maxnconss, TRUE, DEFAULT_MAXNCONSS, 0, INT_MAX, NULL, NULL) );
1026 
1027  SCIP_CALL( SCIPaddIntParam(scip, "separating/" SEPA_NAME "/maxcalls",
1028  "maximum number of overall calls",
1029  &sepadata->maxcalls, TRUE, DEFAULT_MAXCALLS, 0, INT_MAX, NULL, NULL) );
1030 
1031  SCIP_CALL( SCIPaddIntParam(scip, "separating/" SEPA_NAME "/maxnodes",
1032  "maximum number of nodes considered in rapid learning run",
1033  &sepadata->maxnodes, TRUE, DEFAULT_MAXNODES, 0, INT_MAX, NULL, NULL) );
1034 
1035  SCIP_CALL( SCIPaddIntParam(scip, "separating/" SEPA_NAME "/minnodes",
1036  "minimum number of nodes considered in rapid learning run",
1037  &sepadata->minnodes, TRUE, DEFAULT_MINNODES, 0, INT_MAX, NULL, NULL) );
1038 
1039  SCIP_CALL( SCIPaddLongintParam(scip, "separating/" SEPA_NAME "/nwaitingnodes",
1040  "number of nodes that should be processed before rapid learning is executed locally based on the progress of the dualbound",
1041  &sepadata->nwaitingnodes, TRUE, DEFAULT_NWAITINGNODES, 0L, SCIP_LONGINT_MAX, NULL, NULL) );
1042 
1043  SCIP_CALL( SCIPaddBoolParam(scip, "separating/" SEPA_NAME "/copycuts",
1044  "should all active cuts from cutpool be copied to constraints in subproblem?",
1045  &sepadata->copycuts, TRUE, DEFAULT_COPYCUTS, NULL, NULL) );
1046 
1047  return SCIP_OKAY;
1048 }
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
#define SEPA_USESSUBSCIP
int SCIPgetNIntVars(SCIP *scip)
Definition: scip_prob.c:2082
#define DEFAULT_REDUCEDINFER
SCIP_RETCODE SCIPsetSeparating(SCIP *scip, SCIP_PARAMSETTING paramsetting, SCIP_Bool quiet)
Definition: scip_param.c:958
SCIP_Real SCIPgetVarAvgInferences(SCIP *scip, SCIP_VAR *var, SCIP_BRANCHDIR dir)
Definition: scip_var.c:9419
SCIP_RETCODE SCIPtightenVarLb(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound, SCIP_Bool force, SCIP_Bool *infeasible, SCIP_Bool *tightened)
Definition: scip_var.c:5203
SCIP_NODE * SCIPgetCurrentNode(SCIP *scip)
Definition: scip_tree.c:91
SCIP_STAGE SCIPgetStage(SCIP *scip)
Definition: scip_general.c:365
SCIP_Bool SCIPconsIsDynamic(SCIP_CONS *cons)
Definition: cons.c:8349
#define SEPA_FREQ
SCIP_Longint SCIPgetNLPIterations(SCIP *scip)
SCIP_Bool SCIPisFeasLT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
#define DEFAULT_MINNODES
SCIP_CONSHDLR * SCIPfindConshdlr(SCIP *scip, const char *name)
Definition: scip_cons.c:886
SCIP_Real SCIPvarGetLbGlobal(SCIP_VAR *var)
Definition: var.c:17901
SCIP_Longint SCIPgetNSolsFound(SCIP *scip)
static SCIP_RETCODE checkExec(SCIP *scip, SCIP_SEPADATA *sepadata, SCIP_Bool *run)
#define DEFAULT_CONTVARSQUOT
SCIP_Bool SCIPisPositive(SCIP *scip, SCIP_Real val)
SCIP_RETCODE SCIPgetLPDualDegeneracy(SCIP *scip, SCIP_Real *degeneracy, SCIP_Real *varconsratio)
Definition: scip_lp.c:2792
SCIP_Real SCIPvarGetLbLocal(SCIP_VAR *var)
Definition: var.c:17957
#define DEFAULT_LPITERQUOT
static SCIP_DECL_SEPAEXECLP(sepaExeclpRapidlearning)
#define DEFAULT_COPYCUTS
static SCIP_RETCODE setupAndSolveSubscipRapidlearning(SCIP *scip, SCIP *subscip, SCIP_SEPADATA *sepadata, int randseed, SCIP_Bool global, SCIP_RESULT *result)
SCIP_RETCODE SCIPgetVarsData(SCIP *scip, SCIP_VAR ***vars, int *nvars, int *nbinvars, int *nintvars, int *nimplvars, int *ncontvars)
Definition: scip_prob.c:1866
SCIP_CONS ** SCIPconshdlrGetConss(SCIP_CONSHDLR *conshdlr)
Definition: cons.c:4554
SCIP_SOL ** SCIPgetSols(SCIP *scip)
Definition: scip_sol.c:2263
#define FALSE
Definition: def.h:96
SCIP_RETCODE SCIPhashmapCreate(SCIP_HASHMAP **hashmap, BMS_BLKMEM *blkmem, int mapsize)
Definition: misc.c:3024
SCIP_Real SCIPgetVarVSIDS(SCIP *scip, SCIP_VAR *var, SCIP_BRANCHDIR dir)
Definition: scip_var.c:9177
SCIP_RETCODE SCIPaddLongintParam(SCIP *scip, const char *name, const char *desc, SCIP_Longint *valueptr, SCIP_Bool isadvanced, SCIP_Longint defaultvalue, SCIP_Longint minvalue, SCIP_Longint maxvalue, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:111
SCIP_RETCODE SCIPcopyLimits(SCIP *sourcescip, SCIP *targetscip)
Definition: scip_copy.c:3292
int SCIPgetNActivePricers(SCIP *scip)
Definition: scip_pricer.c:348
SCIP_Bool SCIPisNegative(SCIP *scip, SCIP_Real val)
#define TRUE
Definition: def.h:95
const char * SCIPsepaGetName(SCIP_SEPA *sepa)
Definition: sepa.c:743
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_Real SCIPgetLocalLowerbound(SCIP *scip)
Definition: scip_prob.c:3585
methods commonly used by primal heuristics
SCIP_RETCODE SCIPsetPresolving(SCIP *scip, SCIP_PARAMSETTING paramsetting, SCIP_Bool quiet)
Definition: scip_param.c:932
SCIP_RETCODE SCIPtranslateSubSol(SCIP *scip, SCIP *subscip, SCIP_SOL *subsol, SCIP_HEUR *heur, SCIP_VAR **subvars, SCIP_SOL **newsol)
Definition: scip_copy.c:1408
#define DEFAULT_MINDEGENERACY
public methods for problem variables
SCIP_RETCODE SCIPtightenVarUb(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound, SCIP_Bool force, SCIP_Bool *infeasible, SCIP_Bool *tightened)
Definition: scip_var.c:5320
#define SCIPfreeBlockMemory(scip, ptr)
Definition: scip_mem.h:108
void * SCIPhashmapGetImage(SCIP_HASHMAP *hashmap, void *origin)
Definition: misc.c:3211
SCIP_Bool SCIPisEQ(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
#define SCIP_LONGINT_MAX
Definition: def.h:172
#define SCIPfreeBufferArray(scip, ptr)
Definition: scip_mem.h:136
SCIP_RETCODE SCIPcreate(SCIP **scip)
Definition: scip_general.c:292
#define SCIPallocBlockMemory(scip, ptr)
Definition: scip_mem.h:89
SCIP_RETCODE SCIPsetSepaCopy(SCIP *scip, SCIP_SEPA *sepa, SCIP_DECL_SEPACOPY((*sepacopy)))
Definition: scip_sepa.c:151
SCIP_RETCODE SCIPsetRealParam(SCIP *scip, const char *name, SCIP_Real value)
Definition: scip_param.c:603
SCIP_Bool SCIPconsIsRemovable(SCIP_CONS *cons)
Definition: cons.c:8359
void SCIPwarningMessage(SCIP *scip, const char *formatstr,...)
Definition: scip_message.c:120
#define SCIPdebugMsg
Definition: scip_message.h:78
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 SCIPprintStatistics(SCIP *scip, FILE *file)
#define DEFAULT_CHECKDUALBOUND
int SCIPgetNContVars(SCIP *scip)
Definition: scip_prob.c:2172
SCIP_Real SCIPgetLowerboundRoot(SCIP *scip)
#define DEFAULT_APPLYCONFLICTS
SCIP_SEPADATA * SCIPsepaGetData(SCIP_SEPA *sepa)
Definition: sepa.c:633
SCIP_RETCODE SCIPchgVarType(SCIP *scip, SCIP_VAR *var, SCIP_VARTYPE vartype, SCIP_Bool *infeasible)
Definition: scip_var.c:8176
SCIP_Real SCIPvarGetUbGlobal(SCIP_VAR *var)
Definition: var.c:17911
int SCIPsepaGetFreq(SCIP_SEPA *sepa)
Definition: sepa.c:787
SCIP_RETCODE SCIPsolve(SCIP *scip)
Definition: scip_solve.c:2631
SCIP_Bool SCIPisParamFixed(SCIP *scip, const char *name)
Definition: scip_param.c:219
SCIP_RETCODE SCIPinitVarBranchStats(SCIP *scip, SCIP_VAR *var, SCIP_Real downpscost, SCIP_Real uppscost, SCIP_Real downvsids, SCIP_Real upvsids, SCIP_Real downconflen, SCIP_Real upconflen, SCIP_Real downinfer, SCIP_Real upinfer, SCIP_Real downcutoff, SCIP_Real upcutoff)
Definition: scip_var.c:9537
#define DEFAULT_APPLYBDCHGS
SCIP_Real SCIPgetDualbound(SCIP *scip)
#define SEPA_DELAY
int SCIPsepaGetNCallsAtNode(SCIP_SEPA *sepa)
Definition: sepa.c:880
SCIP_RETCODE SCIPsetBoolParam(SCIP *scip, const char *name, SCIP_Bool value)
Definition: scip_param.c:429
SCIP_STATUS SCIPgetStatus(SCIP *scip)
Definition: scip_general.c:483
SCIP_RETCODE SCIPpresolve(SCIP *scip)
Definition: scip_solve.c:2461
SCIP_RETCODE SCIPcopyCuts(SCIP *sourcescip, SCIP *targetscip, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, SCIP_Bool global, int *ncutsadded)
Definition: scip_copy.c:2130
BMS_BLKMEM * SCIPblkmem(SCIP *scip)
Definition: scip_mem.c:57
const char * SCIPconsGetName(SCIP_CONS *cons)
Definition: cons.c:8090
SCIP_Bool SCIPconsIsPropagated(SCIP_CONS *cons)
Definition: cons.c:8309
const char * SCIPvarGetName(SCIP_VAR *var)
Definition: var.c:17242
void SCIPhashmapFree(SCIP_HASHMAP **hashmap)
Definition: misc.c:3058
void SCIPsepaSetData(SCIP_SEPA *sepa, SCIP_SEPADATA *sepadata)
Definition: sepa.c:643
int SCIPgetNRootboundChgs(SCIP *scip)
SCIP_RETCODE SCIPtightenVarLbGlobal(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound, SCIP_Bool force, SCIP_Bool *infeasible, SCIP_Bool *tightened)
Definition: scip_var.c:6228
#define NULL
Definition: lpi_spx1.cpp:164
#define DEFAULT_CHECKEXEC
#define SEPA_PRIORITY
SCIP_RETCODE SCIPgetIntParam(SCIP *scip, const char *name, int *value)
Definition: scip_param.c:269
SCIP_RETCODE SCIPunfixParam(SCIP *scip, const char *name)
Definition: scip_param.c:385
int SCIPgetEffectiveRootDepth(SCIP *scip)
Definition: scip_tree.c:127
#define SCIP_CALL(x)
Definition: def.h:394
SCIP_Real SCIPgetVarAvgConflictlength(SCIP *scip, SCIP_VAR *var, SCIP_BRANCHDIR dir)
Definition: scip_var.c:9365
SCIP_RETCODE SCIPsetEmphasis(SCIP *scip, SCIP_PARAMEMPHASIS paramemphasis, SCIP_Bool quiet)
Definition: scip_param.c:861
#define DEFAULT_MAXNCONSS
SCIP_Bool SCIPisFeasLE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
#define DEFAULT_CHECKNSOLS
#define DEFAULT_CHECKDEGANERACY
int SCIPconshdlrGetNConss(SCIP_CONSHDLR *conshdlr)
Definition: cons.c:4597
#define DEFAULT_MAXNVARS
SCIP_RETCODE SCIPgetConsCopy(SCIP *sourcescip, SCIP *targetscip, SCIP_CONS *sourcecons, SCIP_CONS **targetcons, SCIP_CONSHDLR *sourceconshdlr, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, const char *name, SCIP_Bool initial, SCIP_Bool separate, SCIP_Bool enforce, SCIP_Bool check, SCIP_Bool propagate, SCIP_Bool local, SCIP_Bool modifiable, SCIP_Bool dynamic, SCIP_Bool removable, SCIP_Bool stickingatnode, SCIP_Bool global, SCIP_Bool *valid)
Definition: scip_copy.c:1591
SCIP_RETCODE SCIPincludeSepaBasic(SCIP *scip, SCIP_SEPA **sepa, const char *name, const char *desc, int priority, int freq, SCIP_Real maxbounddist, SCIP_Bool usessubscip, SCIP_Bool delay, SCIP_DECL_SEPAEXECLP((*sepaexeclp)), SCIP_DECL_SEPAEXECSOL((*sepaexecsol)), SCIP_SEPADATA *sepadata)
Definition: scip_sepa.c:109
SCIP_Longint SCIPsepaGetNCalls(SCIP_SEPA *sepa)
Definition: sepa.c:860
SCIP_RETCODE SCIPcopyConsCompression(SCIP *sourcescip, SCIP *targetscip, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, const char *suffix, SCIP_VAR **fixedvars, SCIP_Real *fixedvals, int nfixedvars, SCIP_Bool global, SCIP_Bool enablepricing, SCIP_Bool threadsafe, SCIP_Bool passmessagehdlr, SCIP_Bool *valid)
Definition: scip_copy.c:2965
#define SCIPallocBufferArray(scip, ptr, num)
Definition: scip_mem.h:124
#define DEFAULT_MAXCALLS
#define SCIP_Bool
Definition: def.h:93
#define DEFAULT_MININFLPRATIO
int SCIPgetNImplVars(SCIP *scip)
Definition: scip_prob.c:2127
SCIP_RETCODE SCIPsetObjlimit(SCIP *scip, SCIP_Real objlimit)
Definition: scip_prob.c:1422
int SCIPgetDepth(SCIP *scip)
Definition: scip_tree.c:670
#define MAX(x, y)
Definition: tclique_def.h:92
SCIP_RETCODE SCIPtrySolFree(SCIP *scip, SCIP_SOL **sol, SCIP_Bool printreason, SCIP_Bool completely, SCIP_Bool checkbounds, SCIP_Bool checkintegrality, SCIP_Bool checklprows, SCIP_Bool *stored)
Definition: scip_sol.c:3193
#define DEFAULT_APPLYINFERVALS
SCIP_RETCODE SCIPsetIntParam(SCIP *scip, const char *name, int value)
Definition: scip_param.c:487
SCIP_Bool SCIPconsIsChecked(SCIP_CONS *cons)
Definition: cons.c:8289
SCIP_Bool SCIPconsIsInitial(SCIP_CONS *cons)
Definition: cons.c:8259
SCIP_Real SCIPvarGetObj(SCIP_VAR *var)
Definition: var.c:17749
#define DEFAULT_MINVARCONSRATIO
SCIP_Longint SCIPgetNConflictConssFound(SCIP *scip)
int SCIPgetNSols(SCIP *scip)
Definition: scip_sol.c:2214
SCIP_RETCODE SCIPupdateLocalDualbound(SCIP *scip, SCIP_Real newbound)
Definition: scip_prob.c:3646
SCIP_Real SCIPgetSolOrigObj(SCIP *scip, SCIP_SOL *sol)
Definition: scip_sol.c:1444
int SCIPgetNObjVars(SCIP *scip)
Definition: scip_prob.c:2220
SCIP_Longint SCIPgetNConflictConssApplied(SCIP *scip)
SCIP_Longint SCIPgetNObjlimLeaves(SCIP *scip)
SCIP_Bool SCIPisInfinity(SCIP *scip, SCIP_Real val)
int SCIPgetNBinVars(SCIP *scip)
Definition: scip_prob.c:2037
int SCIPgetNVars(SCIP *scip)
Definition: scip_prob.c:1992
#define SCIP_REAL_MAX
Definition: def.h:187
static SCIP_DECL_SEPAFREE(sepaFreeRapidlearning)
SCIP_RETCODE SCIPsetSepaFree(SCIP *scip, SCIP_SEPA *sepa, SCIP_DECL_SEPAFREE((*sepafree)))
Definition: scip_sepa.c:167
SCIP_RETCODE SCIPincludeSepaRapidlearning(SCIP *scip)
int SCIPgetNConss(SCIP *scip)
Definition: scip_prob.c:3042
#define DEFAULT_CHECKOBJ
SCIP_Real SCIPretransformObj(SCIP *scip, SCIP_Real obj)
Definition: scip_sol.c:1576
SCIP_VAR ** SCIPgetVars(SCIP *scip)
Definition: scip_prob.c:1947
#define SCIP_Real
Definition: def.h:186
SCIP_Bool SCIPisStopped(SCIP *scip)
Definition: scip_general.c:703
#define DEFAULT_CHECKLEAVES
SCIP_Bool SCIPconsIsEnforced(SCIP_CONS *cons)
Definition: cons.c:8279
SCIP_Bool SCIPconsIsSeparated(SCIP_CONS *cons)
Definition: cons.c:8269
rapidlearning separator
#define SCIP_Longint
Definition: def.h:171
SCIP_RETCODE SCIPcheckCopyLimits(SCIP *sourcescip, SCIP_Bool *success)
Definition: scip_copy.c:3249
#define DEFAULT_APPLYPRIMALSOL
SCIP_VARTYPE SCIPvarGetType(SCIP_VAR *var)
Definition: var.c:17407
SCIP_RETCODE SCIPtransformProb(SCIP *scip)
Definition: scip_solve.c:367
SCIP_Bool SCIPisZero(SCIP *scip, SCIP_Real val)
#define SEPA_NAME
SCIP_Bool SCIPisLE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
SCIP_Real SCIPvarGetUbLocal(SCIP_VAR *var)
Definition: var.c:17967
SCIP_RETCODE SCIPtightenVarUbGlobal(SCIP *scip, SCIP_VAR *var, SCIP_Real newbound, SCIP_Bool force, SCIP_Bool *infeasible, SCIP_Bool *tightened)
Definition: scip_var.c:6348
SCIP_Real SCIPgetUpperbound(SCIP *scip)
#define DEFAULT_MAXNODES
#define SEPA_DESC
SCIP_RETCODE SCIPhashmapInsert(SCIP_HASHMAP *hashmap, void *origin, void *image)
Definition: misc.c:3106
#define DEFAULT_NWAITINGNODES
SCIP_RETCODE SCIPaddConflict(SCIP *scip, SCIP_NODE *node, SCIP_CONS *cons, SCIP_NODE *validnode, SCIP_CONFTYPE conftype, SCIP_Bool iscutoffinvolved)
Definition: scip_prob.c:3228
#define SCIP_CALL_ABORT(x)
Definition: def.h:373
#define DEFAULT_APPLYSOLVED
SCIP_VAR * SCIPvarGetTransVar(SCIP_VAR *var)
Definition: var.c:17601
SCIP_Longint SCIPgetNNodes(SCIP *scip)
SCIP_Longint SCIPgetNLPs(SCIP *scip)
SCIP_Longint SCIPgetNInfeasibleLeaves(SCIP *scip)
#define SEPA_MAXBOUNDDIST
SCIP_Bool SCIPvarIsIntegral(SCIP_VAR *var)
Definition: var.c:17433
default SCIP plugins
SCIP_Bool SCIPallowStrongDualReds(SCIP *scip)
Definition: scip_var.c:8629
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_CONTVARS
SCIP_RETCODE SCIPsetSubscipsOff(SCIP *scip, SCIP_Bool quiet)
Definition: scip_param.c:883
static SCIP_DECL_SEPACOPY(sepaCopyRapidlearning)
SCIP_RETCODE SCIPsetLongintParam(SCIP *scip, const char *name, SCIP_Longint value)
Definition: scip_param.c:545
struct SCIP_SepaData SCIP_SEPADATA
Definition: type_sepa.h:52
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
SCIP_RETCODE SCIPfree(SCIP **scip)
Definition: scip_general.c:324