Scippy

SCIP

Solving Constraint Integer Programs

heur_lpface.c
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4 /* SCIP --- Solving Constraint Integer Programs */
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24 
25 /**@file heur_lpface.c
26  * @ingroup DEFPLUGINS_HEUR
27  * @brief lpface primal heuristic that searches the optimal LP face inside a sub-MIP
28  * @author Gregor Hendel
29  */
30 
31 /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32 
33 #include "blockmemshell/memory.h"
34 #include "scip/cons_linear.h"
35 #include "scip/scipdefplugins.h"
36 #include "scip/heur_lpface.h"
37 #include "scip/pub_event.h"
38 #include "scip/pub_heur.h"
39 #include "scip/pub_lp.h"
40 #include "scip/pub_message.h"
41 #include "scip/pub_misc.h"
42 #include "scip/pub_sol.h"
43 #include "scip/pub_tree.h"
44 #include "scip/pub_var.h"
45 #include "scip/scip_branch.h"
46 #include "scip/scip_cons.h"
47 #include "scip/scip_copy.h"
48 #include "scip/scip_event.h"
49 #include "scip/scip_general.h"
50 #include "scip/scip_heur.h"
51 #include "scip/scip_lp.h"
52 #include "scip/scip_mem.h"
53 #include "scip/scip_message.h"
54 #include "scip/scip_nodesel.h"
55 #include "scip/scip_numerics.h"
56 #include "scip/scip_param.h"
57 #include "scip/scip_prob.h"
58 #include "scip/scip_sol.h"
59 #include "scip/scip_solve.h"
60 #include "scip/scip_solvingstats.h"
61 #include "scip/scip_timing.h"
62 #include "scip/scip_tree.h"
63 #include "scip/scip_var.h"
64 #include <string.h>
65 
66 #define HEUR_NAME "lpface"
67 #define HEUR_DESC "LNS heuristic that searches the optimal LP face inside a sub-MIP"
68 #define HEUR_DISPCHAR SCIP_HEURDISPCHAR_LNS
69 #define HEUR_PRIORITY -1104010
70 #define HEUR_FREQ 15
71 #define HEUR_FREQOFS 0
72 #define HEUR_MAXDEPTH -1
73 #define HEUR_TIMING SCIP_HEURTIMING_AFTERLPNODE
74 #define HEUR_USESSUBSCIP TRUE /**< does the heuristic use a secondary SCIP instance? */
75 
76 #define DEFAULT_MAXNODES 5000LL /**< maximum number of nodes to regard in the subproblem */
77 #define DEFAULT_MINNODES 50LL /**< minimum number of nodes to regard in the subproblem */
78 #define DEFAULT_MINFIXINGRATE 0.1 /**< required percentage of fixed integer variables in sub-MIP to run */
79 #define DEFAULT_NODESOFS 200LL /**< number of nodes added to the contingent of the total nodes */
80 #define DEFAULT_NODESQUOT 0.1 /**< subproblem nodes in relation to nodes of the original problem */
81 #define DEFAULT_LPLIMFAC 2.0 /**< factor by which the limit on the number of LP depends on the node limit */
82 #define DEFAULT_USELPROWS TRUE /**< should subproblem be created out of the rows in the LP rows,
83  * otherwise, the copy constructors of the constraints handlers are used */
84 #define DEFAULT_COPYCUTS TRUE /**< if uselprows == FALSE, should all active cuts from cutpool be copied
85  * to constraints in subproblem? */
86 #define DEFAULT_DUALBASISEQUATIONS FALSE /**< should the dually nonbasic rows be turned into equations? */
87 #define DEFAULT_KEEPSUBSCIP FALSE /**< should the heuristic continue solving the same sub-SCIP? */
88 #define DEFAULT_MINPATHLEN 5 /**< the minimum active search tree path length along which the lower bound
89  * hasn't changed before heuristic becomes active */
90 /* event handler properties */
91 #define EVENTHDLR_NAME "Lpface"
92 #define EVENTHDLR_DESC "LP event handler for " HEUR_NAME " heuristic"
93 
94 /*
95  * Data structures
96  */
97 
98 /** data structure to keep sub-SCIP across runs */
99 struct SubscipData
100 {
101  SCIP* subscip; /**< pointer to store sub-SCIP data structure */
102  SCIP_VAR** subvars; /**< array of variables of the sub-problem */
103  int nsubvars; /**< number of sub-problem variables */
104  SCIP_Real objbound; /**< lower bound on objective for when sub SCIP was created */
105 };
106 typedef struct SubscipData SUBSCIPDATA;
108 /** primal heuristic data */
109 struct SCIP_HeurData
110 {
111  SCIP_Longint maxnodes; /**< maximum number of nodes to regard in the subproblem */
112  SCIP_Longint minnodes; /**< minimum number of nodes to regard in the subproblem */
113  SCIP_Longint nodesofs; /**< number of nodes added to the contingent of the total nodes */
114  SCIP_Longint usednodes; /**< nodes already used by lpface in earlier calls */
115  SCIP_Real nodesquot; /**< subproblem nodes in relation to nodes of the original problem */
116 
117  unsigned int nfailures; /**< number of failures since last successful call */
118  SCIP_Longint nextnodenumber; /**< number of nodes at which lpface should be called the next time */
119  SCIP_Real lastlpobjinfeas; /**< last LP objective where the sub-MIP was run to proven infeasibility */
120  SCIP_Real minfixingrate; /**< required percentage of fixed integer variables in sub-MIP to run */
121  SCIP_Real nodelimit; /**< the nodelimit employed in the current sub-SCIP, for the event handler*/
122  SCIP_Real lplimfac; /**< factor by which the limit on the number of LP depends on the node limit */
123  SCIP_Bool uselprows; /**< should subproblem be created out of the rows in the LP rows? */
124  SCIP_Bool copycuts; /**< if uselprows == FALSE, should all active cuts from cutpool be copied
125  * to constraints in subproblem? */
126  SCIP_Bool dualbasisequations; /**< should the dually nonbasic rows be turned into equations? */
127  SCIP_Bool keepsubscip; /**< should the heuristic continue solving the same sub-SCIP? */
128  char subscipobjective; /**< objective function in the sub-SCIP: (z)ero, (r)oot-LP-difference,
129  * (i)nference, LP (f)ractionality, (o)riginal */
130 
131  SCIP_STATUS submipstatus; /**< return status of the sub-MIP */
132  SCIP_Longint submipnlpiters; /**< number of LP iterations of the sub-MIP */
133  SCIP_Real submippresoltime; /**< time required to presolve the sub-MIP */
134  int nvarsfixed; /**< the number of fixed variables by the heuristic */
135  int minpathlen; /**< the minimum active search tree path length along which the lower bound
136  * hasn't changed before heuristic becomes active */
137  SUBSCIPDATA* subscipdata; /**< sub-SCIP data structure */
138 };
139 
140 /*
141  * Local methods
142  */
143 
144 /** determine variable fixings for sub-SCIP based on reduced costs */
145 static
147  SCIP* scip, /**< SCIP data structure */
148  SCIP_HEURDATA* heurdata, /**< primal heuristic data */
149  SCIP_VAR** fixvars, /**< buffer to store variables that should be fixed */
150  SCIP_Real* fixvals, /**< buffer to store corresponding fixing values */
151  int* nfixvars, /**< pointer to store number of variables that should be fixed */
152  SCIP_Bool* success /**< pointer to store whether enough integer variables were fixed */
153  )
154 {
155  SCIP_VAR** vars; /* original scip variables */
156  SCIP_Real fixingrate; /* percentage of variables that are fixed */
157  int nvars;
158  int nbinvars;
159  int nintvars;
160  int i;
161  int fixingcounter;
162 
163  /* get required data of the main scip problem */
164  SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, &nbinvars, &nintvars, NULL, NULL) );
165 
166  fixingcounter = 0;
167 
168  assert(nvars >= nbinvars + nintvars);
169 
170  *nfixvars = 0;
171  /* loop over problem variables and fix all with nonzero reduced costs to their solution value */
172  for( i = 0; i < nvars; i++ )
173  {
174  SCIP_Real solval;
175  SCIP_COL* col;
176  SCIP_Real redcost;
177  SCIP_Real lbglobal;
178  SCIP_Real ubglobal;
179  SCIP_VAR* var;
180 
181  var = vars[i];
182 
183  /* skip non-column variables */
185  continue;
186 
187  /* skip relaxation only variables */
188  if( SCIPvarIsRelaxationOnly(var) )
189  continue;
190 
191  solval = SCIPgetSolVal(scip, NULL, var);
192  col = SCIPvarGetCol(vars[i]);
193  assert(col != NULL);
194  redcost = SCIPgetColRedcost(scip, col);
195  lbglobal = SCIPvarGetLbGlobal(var);
196  ubglobal = SCIPvarGetUbGlobal(var);
197 
198  /* fix the variable to its solution value if variable is nonbasic (i.e., at one of its bounds)
199  * with nonzero reduced costs
200  */
201  if( ! SCIPisDualfeasZero(scip, redcost) )
202  {
203  /* fix variable based on reduced cost information, respecting global bounds */
204  if( (redcost > 0 && SCIPisFeasEQ(scip, solval, lbglobal)) ||
205  (redcost < 0 && SCIPisFeasEQ(scip, solval, ubglobal)) )
206  {
207  assert(! SCIPisInfinity(scip, REALABS(solval)));
208 
209  fixvars[*nfixvars] = var;
210  fixvals[*nfixvars] = solval;
211 
212  if( SCIPvarIsIntegral(var) )
213  ++fixingcounter;
214 
215  ++(*nfixvars);
216  }
217  }
218  }
219 
220  fixingrate = (SCIP_Real)fixingcounter / (SCIP_Real)(MAX(nbinvars + nintvars, 1));
221  heurdata->nvarsfixed = fixingcounter;
222 
223  /* if all variables were fixed or amount of fixed variables is insufficient, skip residual part of
224  * subproblem creation and abort immediately
225  */
226  *success = (fixingcounter < nvars && fixingrate >= heurdata->minfixingrate);
227 
228  SCIPdebugMsg(scip, " LP face heuristic fixed %senough variables (%d out of %d)\n",
229  *success ? "": "not ", fixingcounter, nvars);
230 
231  return SCIP_OKAY;
232 }
233 
234 /** creates the rows of the subproblem */
235 static
237  SCIP* scip, /**< original SCIP data structure */
238  SCIP* subscip, /**< SCIP data structure for the subproblem */
239  SCIP_VAR** subvars, /**< the variables of the subproblem */
240  SCIP_Bool dualbasisequations /**< should the dually nonbasic rows be turned into equations? */
241  )
242 {
243  SCIP_ROW** rows; /* original scip rows */
244 
245  int nrows;
246  int i;
247 
248  /* get the rows and their number */
249  SCIP_CALL( SCIPgetLPRowsData(scip, &rows, &nrows) );
250 
251  /* copy all global rows to linear constraints, unless they contain relaxation-only variables */
252  for( i = 0; i < nrows; i++ )
253  {
254  SCIP_VAR** consvars; /* new constraint's variables */
255  SCIP_COL** cols; /* original row's columns */
256  SCIP_CONS* cons; /* new constraint */
257 
258  SCIP_Real* vals; /* variables' coefficient values of the row */
259  SCIP_Real constant; /* constant added to the row */
260  SCIP_Real lhs; /* left hand side of the row */
261  SCIP_Real rhs; /* left right side of the row */
262  SCIP_Real dualsol;
263  SCIP_Real rowsolactivity;
264  int j;
265  int nnonz;
266 
267  /* ignore rows that are only locally valid */
268  if( SCIProwIsLocal(rows[i]) )
269  continue;
270 
271  /* get the row's data */
272  constant = SCIProwGetConstant(rows[i]);
273  vals = SCIProwGetVals(rows[i]);
274  nnonz = SCIProwGetNNonz(rows[i]);
275  cols = SCIProwGetCols(rows[i]);
276 
277  /* only subtract constant if left hand side is not infinite */
278  lhs = SCIProwGetLhs(rows[i]);
279  if( ! SCIPisInfinity(scip, -lhs) )
280  lhs -= constant;
281 
282  /* only subtract constant if right hand side is not infinite */
283  rhs = SCIProwGetRhs(rows[i]);
284  if( ! SCIPisInfinity(scip, rhs) )
285  rhs -= constant;
286 
287  assert(lhs <= rhs);
288 
289  /* allocate memory array to be filled with the corresponding subproblem variables */
290  SCIP_CALL( SCIPallocBufferArray(scip, &consvars, nnonz) );
291  for( j = 0; j < nnonz; j++ )
292  {
293  consvars[j] = subvars[SCIPvarGetProbindex(SCIPcolGetVar(cols[j]))];
294  if( consvars[j] == NULL )
295  break;
296  }
297  /* skip row if not all variables are in sub-SCIP, i.e., relaxation-only variables */
298  if( j < nnonz )
299  {
300  SCIPfreeBufferArray(scip, &consvars);
301  continue;
302  }
303 
304  dualsol = SCIProwGetDualsol(rows[i]);
305  rowsolactivity = SCIPgetRowActivity(scip, rows[i]);
306 
307  /* transform into equation if the row is sharp and has a nonzero dual solution */
308  if( dualbasisequations && ! SCIPisDualfeasZero(scip, dualsol) )
309  {
310  if( dualsol > 0.0 && SCIPisFeasEQ(scip, rowsolactivity, lhs) )
311  rhs = lhs;
312  else if( dualsol < 0.0 && SCIPisFeasEQ(scip, rowsolactivity, rhs) )
313  lhs = rhs;
314  }
315 
316  /* create a new linear constraint and add it to the subproblem */
317  SCIP_CALL( SCIPcreateConsLinear(subscip, &cons, SCIProwGetName(rows[i]), nnonz, consvars, vals, lhs, rhs,
318  TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, TRUE, TRUE, FALSE) );
319  SCIP_CALL( SCIPaddCons(subscip, cons) );
320  SCIP_CALL( SCIPreleaseCons(subscip, &cons) );
321 
322  /* free temporary memory */
323  SCIPfreeBufferArray(scip, &consvars);
324  }
325 
326  return SCIP_OKAY;
327 }
328 
329 /** create the LP face subproblem constraints */
330 static
332  SCIP* scip, /**< original SCIP data structure */
333  SCIP* subscip, /**< SCIP data structure for the subproblem */
334  SCIP_VAR** subvars, /**< the variables of the subproblem */
335  SCIP_HEURDATA* heurdata /**< primal heuristic data */
336  )
337 {
338  SCIP_VAR** vars = SCIPgetVars(scip);
339  int nvars = SCIPgetNVars(scip);
340  SCIP_Real lowerbound;
341  SCIP_CONS* origobjcons;
342  int i;
343 #ifndef NDEBUG
344  int nobjvars = 0;
345 #endif
346 
347  /* we copy the rows of the LP, if enough variables could be fixed and we work on the MIP relaxation of the problem */
348  if( heurdata->uselprows )
349  {
350  SCIP_CALL( createRows(scip, subscip, subvars, heurdata->dualbasisequations) );
351  }
352 
353  /* add an equation that the objective function must be equal to the lower bound */
354  lowerbound = SCIPgetLowerbound(scip);
355 
356  SCIP_CALL( SCIPcreateConsLinear(subscip, &origobjcons, "objbound_of_origscip", 0, NULL, NULL, lowerbound, lowerbound,
358 
359  for( i = 0; i < nvars; ++i)
360  {
361  if( ! SCIPisZero(subscip, SCIPvarGetObj(vars[i])) )
362  {
363  assert(subvars[i] != NULL); /* a relaxation-only variable cannot have an objective coefficient */
364  SCIP_CALL( SCIPaddCoefLinear(subscip, origobjcons, subvars[i], SCIPvarGetObj(vars[i])) );
365 #ifndef NDEBUG
366  nobjvars++;
367 #endif
368  }
369  }
370  assert(nobjvars == SCIPgetNObjVars(scip));
371 
372  SCIP_CALL( SCIPaddCons(subscip, origobjcons) );
373  SCIP_CALL( SCIPreleaseCons(subscip, &origobjcons) );
374 
375  return SCIP_OKAY;
376 }
377 
378 /** updates heurdata after an unsuccessful run of lpface */
379 static
381  SCIP* scip, /**< original SCIP data structure */
382  SCIP_HEURDATA* heurdata /**< primal heuristic data */
383  )
384 {
385  /* increase number of failures, calculate next node at which lpface should be called and update actual solutions */
386  heurdata->nfailures++;
387  heurdata->nextnodenumber = (heurdata->nfailures <= 25
388  ? SCIPgetNNodes(scip) + 100*(2LL << heurdata->nfailures) /*lint !e703*/
389  : SCIP_LONGINT_MAX);
390 }
391 
392 /** calculate a node limit based on node limiting parameters of the heuristic */
393 static
395  SCIP* scip, /**< (original) SCIP data structure */
396  SCIP_HEUR* heur, /**< LP face heuristic */
397  SCIP_HEURDATA* heurdata /**< primal heuristic data */
398  )
399 {
400  SCIP_Longint nodelimit;
401 
402  /* calculate the maximal number of branching nodes until heuristic is aborted */
403  nodelimit = (SCIP_Longint)(heurdata->nodesquot * SCIPgetNNodes(scip));
404 
405  /* count the setup costs for the sub-MIP as 100 nodes */
406  nodelimit -= 100 * SCIPheurGetNCalls(heur);
407 
408  /* add the offset */
409  nodelimit += heurdata->nodesofs;
410 
411  /* subtract previously used nodes */
412  nodelimit -= heurdata->usednodes;
413 
414  /* do not use more than the maximum number of allowed nodes in one run */
415  nodelimit = MIN(nodelimit, heurdata->maxnodes);
416 
417  /* if the subscip has been kept from a previous run, add the number of already processed nodes */
418  if( heurdata->subscipdata->subscip != NULL )
419  nodelimit += SCIPgetNNodes(heurdata->subscipdata->subscip);
420 
421  return nodelimit;
422 }
423 
424 /** sets node, time, and memory limit according to the parameter settings of the heuristic */
425 static
427  SCIP* scip, /**< original SCIP data structure */
428  SCIP* subscip, /**< data structure of the sub-problem */
429  SCIP_HEUR* heur, /**< LP face heuristic */
430  SCIP_HEURDATA* heurdata, /**< heuristic data structure */
431  SCIP_Bool* success /**< did we successfully set all parameters up? */
432  )
433 {
434  SCIP_Real timelimit;
435  SCIP_Real memorylimit;
436  SCIP_Longint nodelimit;
437  SCIP_Bool avoidmemout;
438 
439  *success = TRUE;
440 
441  /* check whether there is enough time and memory left */
442  SCIP_CALL( SCIPgetRealParam(scip, "limits/time", &timelimit) );
443  SCIP_CALL( SCIPgetRealParam(scip, "limits/memory", &memorylimit) );
444  SCIP_CALL( SCIPgetBoolParam(scip, "misc/avoidmemout", &avoidmemout) );
445 
446  if( ! SCIPisInfinity(scip, timelimit) )
447  timelimit -= SCIPgetSolvingTime(scip);
448 
449  /* substract the memory already used by the main SCIP and the estimated memory usage of external software */
450  if( ! SCIPisInfinity(scip, memorylimit) )
451  {
452  memorylimit -= SCIPgetMemUsed(scip)/1048576.0;
453  memorylimit -= SCIPgetMemExternEstim(scip)/1048576.0;
454  }
455 
456  /* abort if no time is left or not enough memory (we don't abort in this case if misc_avoidmemout == FALSE)
457  * to create a copy of SCIP, including external memory usage */
458  if( timelimit <= 0.0 || (avoidmemout && memorylimit <= 2.0 * SCIPgetMemExternEstim(scip) / 1048576.0) )
459  {
460  *success = FALSE;
461  return SCIP_OKAY;
462  }
463 
464  /* calculate node limit for the subproblem */
465  nodelimit = calcNodeLimit(scip, heur, heurdata);
466 
467  /* we should have aborted the sub-SCIP procedure earlier if no additional nodes are allowed
468  * with the current parameter settings
469  */
470  assert(nodelimit > SCIPgetNNodes(subscip));
471 
472  SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nodelimit) );
473  heurdata->nodelimit = nodelimit;
474 
475  /* set also the other two limits */
476  SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) );
477  SCIP_CALL( SCIPsetRealParam(subscip, "limits/memory", memorylimit) );
478 
479  return SCIP_OKAY;
480 }
481 
482 /** sets all one-time parameter settings like search strategy, but no limits */
483 static
485  SCIP* subscip /**< data structure of the sub-problem */
486  )
487 {
488  /* do not abort subproblem on CTRL-C */
489  SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) );
490 
491  /* for debugging lpface, enable MIP output */
492 #ifdef SCIP_DEBUG
493  SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 5) );
494  SCIP_CALL( SCIPsetIntParam(subscip, "display/freq", 1) );
495 #endif
496 
497  /* disable statistic timing inside sub SCIP */
498  SCIP_CALL( SCIPsetBoolParam(subscip, "timing/statistictiming", FALSE) );
499 
500  /* forbid recursive call of heuristics and separators solving subMIPs */
501  SCIP_CALL( SCIPsetSubscipsOff(subscip, TRUE) );
502 
503  /* disable expensive cutting plane separation */
505 
506  /* disable expensive presolving */
508 
509  /* use restart depth first node selection */
510  if( SCIPfindNodesel(subscip, "restartdfs") != NULL && ! SCIPisParamFixed(subscip, "nodeselection/restartdfs/stdpriority") )
511  {
512  SCIP_CALL( SCIPsetIntParam(subscip, "nodeselection/restartdfs/stdpriority", INT_MAX/4) );
513  }
514 
515  /* use inference branching */
516  if( SCIPfindBranchrule(subscip, "inference") != NULL && ! SCIPisParamFixed(subscip, "branching/inference/priority") )
517  {
518  SCIP_CALL( SCIPsetIntParam(subscip, "branching/inference/priority", INT_MAX/4) );
519  }
520 
521  /* enable conflict analysis, disable analysis of boundexceeding LPs, and restrict conflict pool */
522  if( !SCIPisParamFixed(subscip, "conflict/enable") )
523  {
524  SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/enable", TRUE) );
525  }
526  if( !SCIPisParamFixed(subscip, "conflict/useboundlp") )
527  {
528  SCIP_CALL( SCIPsetCharParam(subscip, "conflict/useboundlp", 'o') );
529  }
530  if( !SCIPisParamFixed(subscip, "conflict/maxstoresize") )
531  {
532  SCIP_CALL( SCIPsetIntParam(subscip, "conflict/maxstoresize", 100) );
533  }
534 
535  return SCIP_OKAY;
536 }
537 
538 /** reset the sub-SCIP data to its default values */
539 static
540 void subscipdataReset(
541  SUBSCIPDATA* subscipdata /**< data structure of the sub-problem */
542  )
543 {
544  subscipdata->subscip = NULL;
545  subscipdata->subvars = NULL;
546  subscipdata->nsubvars = 0;
547  subscipdata->objbound = SCIP_INVALID;
548 }
549 
550 /** free the stored sub-SCIP information */
551 static
553  SCIP* scip, /**< original SCIP data structure */
554  SUBSCIPDATA* subscipdata /**< data structure of the sub-problem */
555  )
556 {
557  assert(subscipdata != NULL);
558 
559  /* free the subscipdata's scip */
560  if( subscipdata->subscip != NULL )
561  {
562  SCIP_CALL( SCIPfree(&subscipdata->subscip) );
563  }
564 
565  subscipdata->subscip = NULL;
566 
567  /* free the subscip variables */
568  if( subscipdata->subvars != NULL )
569  {
570  assert(subscipdata->nsubvars > 0);
571  SCIPfreeBlockMemoryArray(scip, &subscipdata->subvars, subscipdata->nsubvars);
572  }
573 
574  subscipdataReset(subscipdata);
575 
576  return SCIP_OKAY;
577 }
578 
579 /** store the sub-SCIP to the data structure */
580 static
582  SCIP* scip, /**< original SCIP data structure */
583  SUBSCIPDATA* subscipdata, /**< data structure of the sub-problem */
584  SCIP* subscip, /**< sub scip data structure to keep */
585  SCIP_VAR** subvars, /**< sub scip variable array in the order of the main SCIP variables */
586  int nvars /**< number of sub SCIP variables */
587  )
588 {
589  assert(scip != NULL);
590  assert(subscipdata != NULL);
591  assert(subscip != NULL);
592  assert(subvars != NULL);
593  assert(nvars == SCIPgetNVars(scip));
594 
595  assert(subscipdata->subscip == NULL);
596  assert(subscipdata->subvars == NULL);
597 
598  subscipdata->subscip = subscip;
599  SCIP_CALL( SCIPduplicateBlockMemoryArray(scip, &subscipdata->subvars, subvars, nvars) );
600  subscipdata->nsubvars = nvars;
601 
602  subscipdata->objbound = SCIPgetNodeLowerbound(scip, SCIPgetCurrentNode(scip));
603 
604  return SCIP_OKAY;
605 }
606 
607 #ifdef SCIP_DEBUG
608 /** print debug message listing solving time, nodes, and status of sub-SCIP */
609 static
610 SCIP_RETCODE subscipGetInfo(
611  SCIP* scip, /**< SCIP data structure */
612  SCIP* subscip /**< sub SCIP data */
613  )
614 {
615  SCIP_Real timelimit;
616  SCIP_Real memorylimit;
617  SCIP_Longint nodelimit;
618  SCIP_Real time;
619  SCIP_Longint nodes;
620  SCIP_STATUS status;
621 
622  SCIP_CALL( SCIPgetRealParam(subscip, "limits/time", &timelimit) );
623  SCIP_CALL( SCIPgetRealParam(subscip, "limits/memory", &memorylimit) );
624  SCIP_CALL( SCIPgetLongintParam(subscip, "limits/nodes", &nodelimit) );
625 
626  time = SCIPgetSolvingTime(subscip);
627  nodes = SCIPgetNNodes(subscip);
628  status = SCIPgetStatus(subscip);
629 
630  SCIPdebugMsg(scip, "SCIP info: Time: %.1f (Limit: %.1f) Nodes: %"SCIP_LONGINT_FORMAT" (Limit: %"SCIP_LONGINT_FORMAT") Status: %d\n",
631  time, timelimit, nodes, nodelimit, status);
632 
633  return SCIP_OKAY;
634 }
635 #endif
636 
637 /** create the objective function based on the user selection */
638 static
640  SCIP* scip, /**< SCIP data structure */
641  SCIP* subscip, /**< sub-SCIP data structure */
642  SCIP_VAR* var, /**< SCIP variable */
643  SCIP_VAR* subvar, /**< sub-SCIP variable whose objective coefficient is changed */
644  SCIP_HEURDATA* heurdata /**< heuristic data structure to control how the objective is changed */
645  )
646 {
647  SCIP_Real objcoeff;
648  SCIP_Real upfrac;
649  SCIP_Real downfrac;
650  SCIP_Real lpsolval;
651  SCIP_Real rootlpsolval;
652 
653  /* create the objective value based on the choice of the sub-SCIP objective */
654  switch( heurdata->subscipobjective )
655  {
656  /* use zero as objective function */
657  case 'z':
658  objcoeff = 0.0;
659  break;
660 
661  /* use current LP fractionality as objective */
662  case 'f':
663  lpsolval = SCIPvarGetLPSol(var);
664  downfrac = SCIPfrac(scip, lpsolval);
665  upfrac = 1.0 - downfrac;
666 
667  objcoeff = downfrac - upfrac;
668  break;
669 
670  /* use root LP solution difference */
671  case 'r':
672  lpsolval = SCIPvarGetLPSol(var);
673  rootlpsolval = SCIPvarGetRootSol(var);
674  objcoeff = rootlpsolval - lpsolval;
675  break;
676 
677  /* use average inferences */
678  case 'i':
681  break;
682 
683  /* use original objective function */
684  case 'o':
685  objcoeff = SCIPvarGetObj(var);
686  break;
687  default:
688  objcoeff = 0.0;
689  break;
690  }
691 
692  SCIP_CALL( SCIPchgVarObj(subscip, subvar, objcoeff) );
693 
694  return SCIP_OKAY;
695 }
696 
697 /* ---------------- Callback methods of event handler ---------------- */
698 
699 /** execution callback of the event handler for Lpface sub-SCIP
700  *
701  * we interrupt the solution process if we hit the LP iteration limit per node
702  */
703 static
704 SCIP_DECL_EVENTEXEC(eventExecLpface)
705 {
706  SCIP_HEURDATA* heurdata;
708  assert(eventhdlr != NULL);
709  assert(eventdata != NULL);
710  assert(strcmp(SCIPeventhdlrGetName(eventhdlr), EVENTHDLR_NAME) == 0);
711  assert(event != NULL);
712  assert(SCIPeventGetType(event) & SCIP_EVENTTYPE_LPSOLVED);
713 
714  heurdata = (SCIP_HEURDATA*)eventdata;
715  assert(heurdata != NULL);
716 
717  /* interrupt solution process of sub-SCIP */
718  if( SCIPgetNLPs(scip) > heurdata->lplimfac * heurdata->nodelimit )
719  {
720  SCIPdebugMsg(scip, "interrupt after %" SCIP_LONGINT_FORMAT " LPs\n",SCIPgetNLPs(scip));
721  SCIP_CALL( SCIPinterruptSolve(scip) );
722  }
723 
724  return SCIP_OKAY;
725 }
726 
727 /** setup and solve the subproblem and catch the return code */
728 static
730  SCIP* scip, /**< SCIP data structure */
731  SCIP* subscip, /**< sub-SCIP data structure */
732  SCIP_HEURDATA* heurdata, /**< heuristics data */
733  SCIP_VAR** subvars, /**< subproblem's variables */
734  SCIP_VAR** vars, /**< original problem's variables */
735  SCIP_VAR** fixvars, /**< variables that should be fixed */
736  SCIP_Real* fixvals, /**< corresponding fixing values */
737  int nfixvars, /**< number of variables that should be fixed */
738  int nvars /**< number of original problem's variables */
739  )
740 {
741  SCIP_HASHMAP* varmapfw = NULL; /* mapping of SCIP variables to sub-SCIP variables */
742  SCIP_Bool success;
743  int i;
744 
745  assert( subscip != NULL );
746  assert( heurdata != NULL );
747  assert( vars != NULL );
748 
749  /* create the variable hash map */
750  SCIP_CALL( SCIPhashmapCreate(&varmapfw, SCIPblkmem(subscip), nvars) );
751  success = FALSE;
752 
753  if( heurdata->uselprows )
754  {
755  SCIP_Bool valid;
756  char probname[SCIP_MAXSTRLEN];
757 
758  /* copy all plugins */
759  SCIP_CALL( SCIPcopyPlugins(scip, subscip, TRUE, FALSE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE,
760  TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, &valid) );
761  /* get name of the original problem and add the string "_lpfacesub" */
762  (void) SCIPsnprintf(probname, SCIP_MAXSTRLEN, "%s_lpfacesub", SCIPgetProbName(scip));
763 
764  /* create the subproblem */
765  SCIP_CALL( SCIPcreateProbBasic(subscip, probname) );
766  SCIPsetSubscipDepth(subscip, SCIPgetSubscipDepth(scip) + 1);
767 
768  /* copy all variables */
769  SCIP_CALL( SCIPcopyVars(scip, subscip, varmapfw, NULL, fixvars, fixvals, nfixvars, TRUE) );
770 
771  /* copy parameter settings */
772  SCIP_CALL( SCIPcopyParamSettings(scip, subscip) );
773  }
774  else
775  {
776  SCIP_CALL( SCIPcopyConsCompression(scip, subscip, varmapfw, NULL, "lpface", fixvars, fixvals, nfixvars, TRUE, FALSE, FALSE, TRUE, &success) );
777 
778  if( heurdata->copycuts )
779  {
780  /* copies all active cuts from cutpool of sourcescip to linear constraints in targetscip */
781  SCIP_CALL( SCIPcopyCuts(scip, subscip, varmapfw, NULL, TRUE, NULL) );
782  }
783  }
784 
785  /* fill subvars array with mapping from original variables and set the objective coefficient to the desired value */
786  for( i = 0; i < nvars; i++ )
787  {
788  subvars[i] = (SCIP_VAR*) SCIPhashmapGetImage(varmapfw, vars[i]);
789 
790  if( subvars[i] != NULL )
791  {
792  SCIP_CALL( changeSubvariableObjective(scip, subscip, vars[i], subvars[i], heurdata) );
793  }
794  }
795 
796  /* free hash map */
797  SCIPhashmapFree(&varmapfw);
798 
799  /* disable output to console */
800  SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) );
801 
802  /* fix variables that are at their bounds and have nonzero reduced costs */
803  SCIP_CALL( setupSubproblem(scip, subscip, subvars, heurdata) );
804 
805  /* set up sub-SCIP parameters */
806  SCIP_CALL( setSubscipParameters(subscip) );
807 
808  return SCIP_OKAY;
809 }
810 
811 /** setup and solve the subproblem and catch the return code */
812 static
814  SCIP* scip, /**< SCIP data structure */
815  SCIP* subscip, /**< sub-SCIP data structure */
816  SCIP_HEUR* heur, /**< mutation heuristic */
817  SCIP_HEURDATA* heurdata, /**< heuristics data */
818  SCIP_VAR** subvars, /**< subproblem's variables */
819  SCIP_RESULT* result, /**< pointer to store the result */
820  SCIP_Real focusnodelb, /**< lower bound of the focus node */
821  SCIP_Bool* keepthisscip /**< should the subscip be kept or deleted? */
822  )
823 {
824  SCIP_EVENTHDLR* eventhdlr;
825  SCIP_Bool success;
826 
827  assert( scip != NULL );
828  assert( subscip != NULL );
829  assert( heur != NULL );
830  assert( heurdata != NULL );
831  assert( subvars != NULL );
832 
833  /* create event handler for LP events */
834  SCIP_CALL( SCIPincludeEventhdlrBasic(subscip, &eventhdlr, EVENTHDLR_NAME, EVENTHDLR_DESC, eventExecLpface, NULL) );
835  if( eventhdlr == NULL )
836  {
837  SCIPerrorMessage("event handler for " HEUR_NAME " heuristic not found.\n");
838  return SCIP_PLUGINNOTFOUND;
839  }
840 
841  /* determine node, memory, and time limits for the sub-SCIP. Both node and time limit change with every call to
842  * the heuristic
843  */
844  SCIP_CALL( setSubscipLimits(scip, subscip, heur, heurdata, &success) );
845 
846  /* if we did not succeed to set the limits of the subscip to let it run, we won't keep it any longer */
847  if( !success )
848  {
849  *keepthisscip = FALSE;
850 
851  return SCIP_OKAY;
852  }
853 
854  /* catch LP events of sub-SCIP */
855  SCIP_CALL( SCIPtransformProb(subscip) );
856  SCIP_CALL( SCIPcatchEvent(subscip, SCIP_EVENTTYPE_LPSOLVED, eventhdlr, (SCIP_EVENTDATA*) heurdata, NULL) );
857 
858 #ifdef WRITELPFACEPROB
859  {
860  char probfilename[] = "./lpface_prob.mps";
861  char paramfilename[] = "./lpface_prob.set";
862  SCIPinfoMessage(scip, NULL, "Writing problem and parameters to file: <%s> <%s>\n", probfilename, paramfilename);
863  SCIP_CALL( SCIPwriteOrigProblem(subscip, probfilename, NULL, FALSE) );
864  SCIP_CALL( SCIPwriteParams(subscip, paramfilename, TRUE, TRUE) );
865  }
866 #endif
867 
868  /* we must not be infeasible at this stage */
869  assert(SCIPgetStatus(subscip) != SCIP_STATUS_INFEASIBLE);
870 
871  /* solve the subproblem */
872  SCIPdebugMsg(scip, "Solve Lpface subMIP\n");
873  SCIPdebug(
874  SCIP_CALL( subscipGetInfo(scip, subscip) );
875  )
876 
877  /* Errors in solving the subproblem should not kill the overall solving process.
878  * Hence, the return code is caught and a warning is printed, only in debug mode, SCIP will stop.
879  */
880  SCIP_CALL_ABORT( SCIPsolve(subscip) );
881 
882  /* print solving statistics of subproblem if we are in SCIP's debug mode */
884 
885  /* save useful information regarding the subscip runs */
886  heurdata->usednodes += SCIPgetNNodes(subscip);
887  heurdata->submipnlpiters += SCIPgetNLPIterations(subscip);
888  heurdata->submippresoltime += SCIPgetPresolvingTime(subscip);
889  heurdata->submipstatus = SCIPgetStatus(subscip);
890 
891  /* store the focus node lower bound as infeasible to avoid running on this face again */
892  if( heurdata->submipstatus == SCIP_STATUS_INFEASIBLE )
893  {
894  heurdata->lastlpobjinfeas = focusnodelb;
895  *keepthisscip = FALSE;
896  }
897  else if( SCIPgetNSols(subscip) > 0 )
898  {
899  int solindex;
900 
901  /* check, whether a solution was found;
902  * due to numerics, it might happen that not all solutions are feasible -> try all solutions until one is accepted
903  */
904  SCIP_CALL( SCIPtranslateSubSols(scip, subscip, heur, subvars, &success, &solindex) );
905  SCIPdebugMsg(scip, "Transfer was %s successful\n", success ? "" : "not");
906 
907  /* we found an optimal solution and are done. Thus, we free the subscip immediately */
908  if( success )
909  {
910  *keepthisscip = FALSE;
911  *result = SCIP_FOUNDSOL;
912  }
913 
914  /* if solution could not be added to problem => run is counted as a failure */
915  if( ! success || solindex != SCIPsolGetIndex(SCIPgetBestSol(scip)) )
916  updateFailureStatistic(scip, heurdata);
917  }
918  else
919  {
920  /* if no new solution was found, run was a failure */
921  updateFailureStatistic(scip, heurdata);
922  }
923 
924  return SCIP_OKAY;
925 }
926 
927 /*
928  * Callback methods of primal heuristic
929  */
930 
931 /** copy method for primal heuristic plugins (called when SCIP copies plugins) */
932 static
933 SCIP_DECL_HEURCOPY(heurCopyLpface)
934 { /*lint --e{715}*/
935  assert(scip != NULL);
936  assert(heur != NULL);
937  assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0);
938 
939  /* call inclusion method of primal heuristic */
941 
942  return SCIP_OKAY;
943 }
944 
945 /** destructor of primal heuristic to free user data (called when SCIP is exiting) */
946 static
947 SCIP_DECL_HEURFREE(heurFreeLpface)
948 { /*lint --e{715}*/
949  SCIP_HEURDATA* heurdata;
951  assert(heur != NULL);
952  assert(scip != NULL);
953 
954  /* get heuristic data */
955  heurdata = SCIPheurGetData(heur);
956  assert(heurdata != NULL);
957 
958  /* free heuristic data */
959  SCIPfreeBlockMemory(scip, &heurdata);
960  SCIPheurSetData(heur, NULL);
961 
962  return SCIP_OKAY;
963 }
964 
965 /** initialization method of primal heuristic (called after problem was transformed) */
966 static
967 SCIP_DECL_HEURINIT(heurInitLpface)
968 { /*lint --e{715}*/
969  SCIP_HEURDATA* heurdata;
971  assert(heur != NULL);
972  assert(scip != NULL);
973 
974  /* get heuristic's data */
975  heurdata = SCIPheurGetData(heur);
976  assert(heurdata != NULL);
977 
978  /* initialize data */
979  heurdata->usednodes = 0;
980  heurdata->nfailures = 0;
981  heurdata->nextnodenumber = 0;
982 
983  heurdata->submipstatus = SCIP_STATUS_UNKNOWN;
984  heurdata->submipnlpiters = -1;
985  heurdata->submippresoltime = 0.0;
986  heurdata->nvarsfixed = -1;
987 
988  return SCIP_OKAY;
989 }
990 
991 /** solving process initialization method of primal heuristic (called when branch and bound process is about to begin) */
992 static
993 SCIP_DECL_HEURINITSOL(heurInitsolLpface)
994 { /*lint --e{715}*/
995  SCIP_HEURDATA* heurdata;
997  assert(heur != NULL);
998  assert(scip != NULL);
999 
1000  /* get heuristic's data */
1001  heurdata = SCIPheurGetData(heur);
1002  assert(heurdata != NULL);
1003 
1004  /* reset the last infeasible objective because it lives in transformed space and must be invalidated at every restart */
1005  heurdata->lastlpobjinfeas = -SCIPinfinity(scip);
1006 
1007  assert(heurdata->subscipdata == NULL);
1008 
1009  /* variable order might have changed since the last run, reinitialize sub-SCIP data */
1010  SCIP_CALL( SCIPallocBlockMemory(scip, &heurdata->subscipdata) );
1011  subscipdataReset(heurdata->subscipdata);
1012 
1013  return SCIP_OKAY;
1014 }
1015 
1016 /** solving process deinitialization method of primal heuristic (called before branch and bound process is exiting) */
1017 static
1018 SCIP_DECL_HEUREXITSOL(heurExitsolLpface)
1019 { /*lint --e{715}*/
1020  SCIP_HEURDATA* heurdata;
1022  assert(heur != NULL);
1023  assert(scip != NULL);
1024 
1025  /* get heuristic's data */
1026  heurdata = SCIPheurGetData(heur);
1027  assert(heurdata != NULL);
1028 
1029  /* variable order might change after restart, free the heuristic subscipdata */
1030  assert(heurdata->keepsubscip || heurdata->subscipdata->subscip == NULL);
1031  if( heurdata->subscipdata->subscip != NULL )
1032  {
1033  /* free kept data structures first */
1034  SCIP_CALL( subscipdataFreeSubscip(scip, heurdata->subscipdata) );
1035  }
1036 
1037  /* free the sub-SCIP data structure */
1038  SCIPfreeBlockMemory(scip, &heurdata->subscipdata);
1039 
1040  return SCIP_OKAY;
1041 }
1042 
1043 #ifdef SCIP_STATISTIC
1044 /** deinitialization method of primal heuristic (called before transformed problem is freed) */
1045 static
1047 { /*lint --e{715}*/
1048  SCIP_HEURDATA* heurdata;
1049 
1050  assert(heur != NULL);
1051  assert(scip != NULL);
1052 
1053  /* get heuristic's data */
1054  heurdata = SCIPheurGetData(heur);
1055  assert(heurdata != NULL);
1056 
1058  "LP Face heuristic stats: Status: %d Nodes: %d LP iters: %d Fixed: %d Presolving time: %.2f\n",
1059  heurdata->submipstatus, heurdata->usednodes, heurdata->submipnlpiters, heurdata->nvarsfixed, heurdata->submippresoltime);
1060 
1061  return SCIP_OKAY;
1062 }
1063 #else
1064 #define heurExitLpface NULL
1065 #endif
1066 
1067 /** execution method of primal heuristic */
1068 static
1069 SCIP_DECL_HEUREXEC(heurExecLpface)
1070 { /*lint --e{715}*/
1071  SCIP* subscip; /* the subproblem created by lpface */
1072  SCIP_HEURDATA* heurdata; /* primal heuristic data */
1073  SCIP_VAR** vars; /* original problem's variables */
1074  SCIP_VAR** subvars; /* subproblem's variables */
1075  SCIP_RETCODE retcode;
1076  SCIP_Bool keepthisscip;
1077  SCIP_Real focusnodelb;
1078  SCIP_Real rootlb;
1079  SCIP_Longint nodelimit; /* node limit for the subproblem */
1080  int nvars; /* number of original problem's variables */
1081  int nbinvars;
1082  int nintvars;
1083 
1084  assert(heur != NULL);
1085  assert(scip != NULL);
1086  assert(result != NULL);
1087 
1088  /* get heuristic's data */
1089  heurdata = SCIPheurGetData(heur);
1090  assert(heurdata != NULL);
1091 
1092  *result = SCIP_DELAYED;
1093 
1094  /* we skip infeasible nodes */
1095  if( nodeinfeasible )
1096  return SCIP_OKAY;
1097 
1098  /* the node number to run the heuristic again was not yet reached */
1099  if( SCIPgetNNodes(scip) < heurdata->nextnodenumber )
1100  return SCIP_OKAY;
1101 
1102  /* do not run heuristic on nodes that were not solved to optimality */
1104  return SCIP_OKAY;
1105 
1106  /* LP face requires that the LP defines a valid lower bound for the current node */
1107  if( ! SCIPisLPRelax(scip) || ! SCIPallColsInLP(scip) )
1108  return SCIP_OKAY;
1109 
1110  assert(SCIPgetCurrentNode(scip) != NULL);
1111  focusnodelb = SCIPgetNodeLowerbound(scip, SCIPgetCurrentNode(scip));
1112 
1113  /* from the checked conditions, the LP objective should be a valid lower bound for the current node */
1114  assert(SCIPisGE(scip, focusnodelb, SCIPgetLPObjval(scip)));
1115 
1116  /* do not run if the current focus node already has a lower bound higher than the LP value at the node,
1117  * for example, due to strong branching
1118  */
1119  if( SCIPisGT(scip, focusnodelb, SCIPgetLPObjval(scip)) )
1120  return SCIP_OKAY;
1121 
1122  /* delay heuristic if the active search tree path is not deep enough */
1123  if( SCIPgetDepth(scip) < heurdata->minpathlen - 1 )
1124  return SCIP_OKAY;
1125 
1126  /* only run at lower bound defining nodes */
1127  if( SCIPisGT(scip, focusnodelb, SCIPgetLowerbound(scip)) )
1128  return SCIP_OKAY;
1129 
1130  /* only run if lower bound has increased since last LP objective where the sub-MIP was solved to infeasibility */
1131  if( SCIPisEQ(scip, heurdata->lastlpobjinfeas, focusnodelb) )
1132  return SCIP_OKAY;
1133 
1134  /* make the reasoning stronger if the objective value must be integral */
1135  if( SCIPisObjIntegral(scip)
1136  && (! SCIPisIntegral(scip, focusnodelb) || SCIPisLT(scip, focusnodelb, heurdata->lastlpobjinfeas + 1.0)) )
1137  return SCIP_OKAY;
1138 
1139  rootlb = SCIPgetLowerboundRoot(scip);
1140  assert(SCIPisLE(scip, rootlb, focusnodelb));
1141 
1142  /* if the lower bound hasn't changed since the root node, we want to run anyway, otherwise we base our decision on the
1143  * total path length of the active search tree along which the lower bound did not change anymore.
1144  */
1145  if( SCIPisLT(scip, rootlb, focusnodelb) )
1146  {
1147  SCIP_NODE* parent;
1148  int nonimprovingpathlen = 0; /* the length of the current path (in edges) along which the lower bound stayed the same */
1149 
1150  parent = SCIPnodeGetParent(SCIPgetCurrentNode(scip));
1151 
1152  /* count the path length along which the dual bound has not changed */
1153  while( SCIPisEQ(scip, SCIPnodeGetLowerbound(parent), focusnodelb) && nonimprovingpathlen < heurdata->minpathlen )
1154  {
1155  ++nonimprovingpathlen;
1156 
1157  /* we cannot hit the root node because the root lower bound is strictly smaller */
1158  assert(SCIPnodeGetParent(parent) != NULL);
1159  parent = SCIPnodeGetParent(parent);
1160  }
1161 
1162  /* we return if the nonimproving path is too short measured by the heuristic frequency */
1163  if( nonimprovingpathlen < heurdata->minpathlen )
1164  {
1165  /* we do not delay the heuristic if the path has length zero, otherwise it may be called at children so that
1166  * the path length is sufficient
1167  */
1168  if( nonimprovingpathlen == 0 )
1169  *result = SCIP_DIDNOTRUN;
1170 
1171  return SCIP_OKAY;
1172  }
1173  }
1174 
1175  *result = SCIP_DIDNOTRUN;
1176 
1177  /* calculate the maximal number of branching nodes until heuristic is aborted */
1178  nodelimit = calcNodeLimit(scip, heur, heurdata);
1179 
1180  /* check whether we have enough nodes left to call subproblem solving */
1181  if( nodelimit < heurdata->minnodes )
1182  return SCIP_OKAY;
1183 
1184  if( SCIPisStopped(scip) )
1185  return SCIP_OKAY;
1186 
1187  SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, &nbinvars, &nintvars, NULL, NULL) );
1188  assert(nvars > 0);
1189 
1190  /* check whether discrete variables are present */
1191  if( nbinvars == 0 && nintvars == 0 )
1192  return SCIP_OKAY;
1193 
1194  *result = SCIP_DIDNOTFIND;
1195 
1196  keepthisscip = heurdata->keepsubscip;
1197 
1198  /* check if variable number increased since last call to the sub-SCIP */
1199  if( heurdata->subscipdata->subscip != NULL && heurdata->subscipdata->nsubvars != nvars )
1200  {
1201  SCIPdebugMsg(scip, "Free subscip of LP face heuristic because variable number %d changed since last call (was %d)\n",
1202  nvars, heurdata->subscipdata->nsubvars);
1203 
1204  SCIP_CALL( subscipdataFreeSubscip(scip, heurdata->subscipdata) );
1205  }
1206  else if( heurdata->subscipdata->subscip != NULL && SCIPisGT(scip, focusnodelb, heurdata->subscipdata->objbound) )
1207  {
1208  SCIPdebugMsg(scip, "Free subscip of LP face heuristic because of different dual bound: %16.9g > %16.9g\n",
1209  SCIPretransformObj(scip, focusnodelb), SCIPretransformObj(scip, heurdata->subscipdata->objbound));
1210 
1211  SCIP_CALL( subscipdataFreeSubscip(scip, heurdata->subscipdata) );
1212  }
1213 
1214  /* retrieve the sub-SCIP from the heuristic data structure */
1215  if( heurdata->subscipdata->subscip != NULL )
1216  {
1217  subscip = heurdata->subscipdata->subscip;
1218  subvars = heurdata->subscipdata->subvars;
1219  nvars = heurdata->subscipdata->nsubvars;
1220 
1221  SCIPdebug(
1222  SCIPdebugMsg(scip, "Loaded sub-SCIP from previous run:\n");
1223  SCIP_CALL( subscipGetInfo(scip, subscip) );
1224  )
1225  }
1226  else
1227  {
1228  SCIP_VAR** fixvars;
1229  SCIP_Real* fixvals;
1230  int nfixvars;
1231  SCIP_Bool success;
1232 
1233  assert(heurdata->subscipdata->subscip == NULL);
1234 
1235  /* allocate memory to hold sub-SCIP variables */
1236  SCIP_CALL( SCIPallocBufferArray(scip, &subvars, nvars) );
1237 
1238  SCIP_CALL( SCIPallocBufferArray(scip, &fixvars, nvars) );
1239  SCIP_CALL( SCIPallocBufferArray(scip, &fixvals, nvars) );
1240 
1241  SCIP_CALL( determineVariableFixings(scip, heurdata, fixvars, fixvals, &nfixvars, &success) );
1242 
1243  if( ! success )
1244  {
1245  SCIPfreeBufferArray(scip, &fixvals);
1246  SCIPfreeBufferArray(scip, &fixvars);
1247  SCIPfreeBufferArray(scip, &subvars);
1248 
1249  *result = SCIP_DIDNOTRUN;
1250  return SCIP_OKAY;
1251  }
1252 
1253  SCIPdebugMsg(scip, "Creating new sub-Problem for LP face heuristic\n");
1254 
1255  /* initialize the subproblem */
1256  SCIP_CALL( SCIPcreate(&subscip) );
1257 
1258  SCIP_CALL( setupSubscipLpface(scip, subscip, heurdata, subvars, vars, fixvars, fixvals, nfixvars, nvars) );
1259 
1260  SCIPfreeBufferArray(scip, &fixvals);
1261  SCIPfreeBufferArray(scip, &fixvars);
1262  }
1263 
1264  retcode = solveSubscipLpface(scip, subscip, heur, heurdata, subvars, result, focusnodelb, &keepthisscip);
1265 
1266  SCIP_CALL( retcode );
1267 
1268  /* free subproblem or store it for the next run of the heuristic */
1269  if( ! keepthisscip )
1270  {
1271  /* we only allocated buffer memory if no previous subscip was reinstalled */
1272  if( heurdata->subscipdata->subscip == NULL )
1273  {
1274  SCIPfreeBufferArray(scip, &subvars);
1275  SCIP_CALL( SCIPfree(&subscip) );
1276  }
1277  else
1278  SCIP_CALL( subscipdataFreeSubscip(scip, heurdata->subscipdata) );
1279 
1280  subscipdataReset(heurdata->subscipdata);
1281  }
1282  else
1283  {
1284  /* if the subscip has not yet been stored, we copy the subscip into the heuristic data to keep it for the next run */
1285  if( heurdata->subscipdata->subscip == NULL )
1286  {
1287  SCIP_CALL( subscipdataCopySubscip(scip, heurdata->subscipdata, subscip, subvars, nvars) );
1288  SCIPfreeBufferArray(scip, &subvars);
1289  }
1290  else
1291  {
1292  assert(heurdata->subscipdata->subscip == subscip);
1293  assert(heurdata->subscipdata->subvars == subvars);
1294  assert(heurdata->subscipdata->nsubvars == nvars);
1295  }
1296  }
1297 
1298  return SCIP_OKAY;
1299 }
1300 
1301 /*
1302  * primal heuristic specific interface methods
1303  */
1304 
1305 /** creates the lpface primal heuristic and includes it in SCIP */
1307  SCIP* scip /**< SCIP data structure */
1308  )
1310  SCIP_HEURDATA* heurdata;
1311  SCIP_HEUR* heur;
1312 
1313  /* create Lpface primal heuristic data */
1314  SCIP_CALL( SCIPallocBlockMemory(scip, &heurdata) );
1315 
1316  heurdata->subscipdata = NULL;
1317 
1318  /* include primal heuristic */
1319  SCIP_CALL( SCIPincludeHeurBasic(scip, &heur,
1321  HEUR_MAXDEPTH, HEUR_TIMING, HEUR_USESSUBSCIP, heurExecLpface, heurdata) );
1322 
1323  assert(heur != NULL);
1324 
1325  /* set non-NULL pointers to callback methods */
1326  SCIP_CALL( SCIPsetHeurCopy(scip, heur, heurCopyLpface) );
1327  SCIP_CALL( SCIPsetHeurFree(scip, heur, heurFreeLpface) );
1328  SCIP_CALL( SCIPsetHeurInit(scip, heur, heurInitLpface) );
1329  SCIP_CALL( SCIPsetHeurInitsol(scip, heur, heurInitsolLpface) );
1330  SCIP_CALL( SCIPsetHeurExitsol(scip, heur, heurExitsolLpface) );
1331  SCIP_CALL( SCIPsetHeurExit(scip, heur, heurExitLpface) );
1332 
1333  /* add lpface primal heuristic parameters */
1334  SCIP_CALL( SCIPaddLongintParam(scip, "heuristics/" HEUR_NAME "/nodesofs",
1335  "number of nodes added to the contingent of the total nodes",
1336  &heurdata->nodesofs, FALSE, DEFAULT_NODESOFS, 0LL, SCIP_LONGINT_MAX, NULL, NULL) );
1337 
1338  SCIP_CALL( SCIPaddLongintParam(scip, "heuristics/" HEUR_NAME "/maxnodes",
1339  "maximum number of nodes to regard in the subproblem",
1340  &heurdata->maxnodes, TRUE, DEFAULT_MAXNODES, 0LL, SCIP_LONGINT_MAX, NULL, NULL) );
1341 
1342  SCIP_CALL( SCIPaddLongintParam(scip, "heuristics/" HEUR_NAME "/minnodes",
1343  "minimum number of nodes required to start the subproblem",
1344  &heurdata->minnodes, TRUE, DEFAULT_MINNODES, 0LL, SCIP_LONGINT_MAX, NULL, NULL) );
1345 
1346  SCIP_CALL( SCIPaddRealParam(scip, "heuristics/" HEUR_NAME "/nodesquot",
1347  "contingent of sub problem nodes in relation to the number of nodes of the original problem",
1348  &heurdata->nodesquot, FALSE, DEFAULT_NODESQUOT, 0.0, 1.0, NULL, NULL) );
1349 
1350  SCIP_CALL( SCIPaddRealParam(scip, "heuristics/" HEUR_NAME "/minfixingrate",
1351  "required percentage of fixed integer variables in sub-MIP to run",
1352  &heurdata->minfixingrate, FALSE, DEFAULT_MINFIXINGRATE, 0.0, 1.0, NULL, NULL) );
1353 
1354  SCIP_CALL( SCIPaddRealParam(scip, "heuristics/" HEUR_NAME "/lplimfac",
1355  "factor by which the limit on the number of LP depends on the node limit",
1356  &heurdata->lplimfac, TRUE, DEFAULT_LPLIMFAC, 1.0, SCIP_REAL_MAX, NULL, NULL) );
1357 
1358  SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/uselprows",
1359  "should subproblem be created out of the rows in the LP rows?",
1360  &heurdata->uselprows, TRUE, DEFAULT_USELPROWS, NULL, NULL) );
1361 
1362  SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/dualbasisequations",
1363  "should dually nonbasic rows be turned into equations?",
1364  &heurdata->dualbasisequations, TRUE, DEFAULT_DUALBASISEQUATIONS, NULL, NULL) );
1365 
1366  SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/keepsubscip",
1367  "should the heuristic continue solving the same sub-SCIP?",
1368  &heurdata->keepsubscip, TRUE, DEFAULT_KEEPSUBSCIP, NULL, NULL) );
1369 
1370  SCIP_CALL( SCIPaddBoolParam(scip, "heuristics/" HEUR_NAME "/copycuts",
1371  "if uselprows == FALSE, should all active cuts from cutpool be copied to constraints in subproblem?",
1372  &heurdata->copycuts, TRUE, DEFAULT_COPYCUTS, NULL, NULL) );
1373 
1374  SCIP_CALL( SCIPaddCharParam(scip, "heuristics/" HEUR_NAME "/subscipobjective",
1375  "objective function in the sub-SCIP: (z)ero, (r)oot-LP-difference, (i)nference, LP (f)ractionality, (o)riginal",
1376  &heurdata->subscipobjective, TRUE, 'z', "forzi", NULL, NULL) );
1377 
1378  SCIP_CALL( SCIPaddIntParam(scip, "heuristics/" HEUR_NAME "/minpathlen",
1379  "the minimum active search tree path length along which lower bound hasn't changed before heuristic becomes active",
1380  &heurdata->minpathlen, TRUE, DEFAULT_MINPATHLEN, 0, 65531, NULL, NULL) );
1381 
1382  return SCIP_OKAY;
1383 }
enum SCIP_Result SCIP_RESULT
Definition: type_result.h:61
SCIP_RETCODE SCIPsetHeurExitsol(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEUREXITSOL((*heurexitsol)))
Definition: scip_heur.c:242
#define SCIPfreeBlockMemoryArray(scip, ptr, num)
Definition: scip_mem.h:110
SCIP_Real SCIPgetSolvingTime(SCIP *scip)
Definition: scip_timing.c:378
#define SCIP_EVENTTYPE_LPSOLVED
Definition: type_event.h:101
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_Bool SCIPisFeasEQ(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
public methods for SCIP parameter handling
SCIP_NODE * SCIPgetCurrentNode(SCIP *scip)
Definition: scip_tree.c:91
public methods for branch and bound tree
#define DEFAULT_USELPROWS
Definition: heur_lpface.c:82
SCIP_Longint SCIPgetNLPIterations(SCIP *scip)
#define EVENTHDLR_DESC
Definition: heur_lpface.c:95
public methods for node selector plugins
public methods for memory management
#define DEFAULT_NODESOFS
Definition: heur_lpface.c:79
SCIP_Real SCIPnodeGetLowerbound(SCIP_NODE *node)
Definition: tree.c:7456
SCIP_Real SCIPvarGetLbGlobal(SCIP_VAR *var)
Definition: var.c:17923
SCIP_RETCODE SCIPgetRealParam(SCIP *scip, const char *name, SCIP_Real *value)
Definition: scip_param.c:307
#define SCIP_MAXSTRLEN
Definition: def.h:302
#define HEUR_FREQOFS
Definition: heur_lpface.c:71
SCIP_RETCODE SCIPsetHeurExit(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEUREXIT((*heurexit)))
Definition: scip_heur.c:210
int SCIProwGetNNonz(SCIP_ROW *row)
Definition: lp.c:17216
SCIP_Real SCIPgetColRedcost(SCIP *scip, SCIP_COL *col)
Definition: scip_lp.c:1154
SCIP_Bool SCIPisGE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
#define HEUR_PRIORITY
Definition: heur_lpface.c:69
public solving methods
SCIP_RETCODE SCIPincludeEventhdlrBasic(SCIP *scip, SCIP_EVENTHDLR **eventhdlrptr, const char *name, const char *desc, SCIP_DECL_EVENTEXEC((*eventexec)), SCIP_EVENTHDLRDATA *eventhdlrdata)
Definition: scip_event.c:104
public methods for timing
const char * SCIProwGetName(SCIP_ROW *row)
Definition: lp.c:17354
SCIP_NODE * SCIPnodeGetParent(SCIP_NODE *node)
Definition: tree.c:7716
static SCIP_Longint calcNodeLimit(SCIP *scip, SCIP_HEUR *heur, SCIP_HEURDATA *heurdata)
Definition: heur_lpface.c:397
#define heurExitLpface
Definition: heur_lpface.c:1067
#define DEFAULT_MAXNODES
Definition: heur_lpface.c:76
static SCIP_RETCODE determineVariableFixings(SCIP *scip, SCIP_HEURDATA *heurdata, SCIP_VAR **fixvars, SCIP_Real *fixvals, int *nfixvars, SCIP_Bool *success)
Definition: heur_lpface.c:149
SCIP_Real SCIPvarGetRootSol(SCIP_VAR *var)
Definition: var.c:13362
SCIP_RETCODE SCIPgetVarsData(SCIP *scip, SCIP_VAR ***vars, int *nvars, int *nbinvars, int *nintvars, int *nimplvars, int *ncontvars)
Definition: scip_prob.c:1874
static SCIP_RETCODE createRows(SCIP *scip, SCIP *subscip, SCIP_VAR **subvars, SCIP_Bool dualbasisequations)
Definition: heur_lpface.c:239
SCIP_Real SCIProwGetLhs(SCIP_ROW *row)
Definition: lp.c:17295
#define FALSE
Definition: def.h:96
SCIP_RETCODE SCIPhashmapCreate(SCIP_HASHMAP **hashmap, BMS_BLKMEM *blkmem, int mapsize)
Definition: misc.c:3024
void SCIPsetSubscipDepth(SCIP *scip, int newdepth)
Definition: scip_copy.c:2621
const char * SCIPeventhdlrGetName(SCIP_EVENTHDLR *eventhdlr)
Definition: event.c:324
SCIP_RETCODE SCIPincludeHeurLpface(SCIP *scip)
Definition: heur_lpface.c:1309
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
int SCIPgetSubscipDepth(SCIP *scip)
Definition: scip_copy.c:2600
SCIP_Real SCIPinfinity(SCIP *scip)
int SCIPsnprintf(char *t, int len, const char *s,...)
Definition: misc.c:10788
#define TRUE
Definition: def.h:95
#define SCIPdebug(x)
Definition: pub_message.h:93
#define HEUR_MAXDEPTH
Definition: heur_lpface.c:72
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63
SCIP_RETCODE SCIPwriteOrigProblem(SCIP *scip, const char *filename, const char *extension, SCIP_Bool genericnames)
Definition: scip_prob.c:609
SCIP_RETCODE SCIPsetPresolving(SCIP *scip, SCIP_PARAMSETTING paramsetting, SCIP_Bool quiet)
Definition: scip_param.c:932
SCIP_BRANCHRULE * SCIPfindBranchrule(SCIP *scip, const char *name)
Definition: scip_branch.c:297
int SCIPvarGetProbindex(SCIP_VAR *var)
Definition: var.c:17613
SCIP_Bool SCIPisDualfeasZero(SCIP *scip, SCIP_Real val)
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
#define DEFAULT_KEEPSUBSCIP
Definition: heur_lpface.c:89
SCIP_RETCODE SCIPtranslateSubSols(SCIP *scip, SCIP *subscip, SCIP_HEUR *heur, SCIP_VAR **subvars, SCIP_Bool *success, int *solindex)
Definition: scip_copy.c:1448
#define DEFAULT_NODESQUOT
Definition: heur_lpface.c:80
#define HEUR_DISPCHAR
Definition: heur_lpface.c:68
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
void SCIPheurSetData(SCIP_HEUR *heur, SCIP_HEURDATA *heurdata)
Definition: heur.c:1371
#define SCIPallocBlockMemory(scip, ptr)
Definition: scip_mem.h:89
public methods for SCIP variables
SCIP_RETCODE SCIPsetRealParam(SCIP *scip, const char *name, SCIP_Real value)
Definition: scip_param.c:603
SCIP_RETCODE SCIPcopyPlugins(SCIP *sourcescip, SCIP *targetscip, SCIP_Bool copyreaders, SCIP_Bool copypricers, SCIP_Bool copyconshdlrs, SCIP_Bool copyconflicthdlrs, SCIP_Bool copypresolvers, SCIP_Bool copyrelaxators, SCIP_Bool copyseparators, SCIP_Bool copycutselectors, SCIP_Bool copypropagators, SCIP_Bool copyheuristics, SCIP_Bool copyeventhdlrs, SCIP_Bool copynodeselectors, SCIP_Bool copybranchrules, SCIP_Bool copydisplays, SCIP_Bool copydialogs, SCIP_Bool copytables, SCIP_Bool copyexprhdlrs, SCIP_Bool copynlpis, SCIP_Bool passmessagehdlr, SCIP_Bool *valid)
Definition: scip_copy.c:275
SCIP_Real SCIProwGetDualsol(SCIP_ROW *row)
Definition: lp.c:17315
#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 SCIPcopyParamSettings(SCIP *sourcescip, SCIP *targetscip)
Definition: scip_copy.c:2559
static SCIP_DECL_HEUREXITSOL(heurExitsolLpface)
Definition: heur_lpface.c:1021
SCIP_Real SCIPgetPresolvingTime(SCIP *scip)
Definition: scip_timing.c:442
SCIP_RETCODE SCIPprintStatistics(SCIP *scip, FILE *file)
SCIP_RETCODE SCIPaddCoefLinear(SCIP *scip, SCIP_CONS *cons, SCIP_VAR *var, SCIP_Real val)
void SCIPinfoMessage(SCIP *scip, FILE *file, const char *formatstr,...)
Definition: scip_message.c:208
SCIP_RETCODE SCIPcreateProbBasic(SCIP *scip, const char *name)
Definition: scip_prob.c:180
SCIP_Real SCIPgetLowerboundRoot(SCIP *scip)
public methods for numerical tolerances
public methods for querying solving statistics
const char * SCIPgetProbName(SCIP *scip)
Definition: scip_prob.c:1075
public methods for the branch-and-bound tree
SCIP_Bool SCIPisLPRelax(SCIP *scip)
Definition: scip_lp.c:225
static SCIP_RETCODE subscipdataFreeSubscip(SCIP *scip, SUBSCIPDATA *subscipdata)
Definition: heur_lpface.c:555
SCIP_Real SCIPvarGetUbGlobal(SCIP_VAR *var)
Definition: var.c:17933
#define SCIPduplicateBlockMemoryArray(scip, ptr, source, num)
Definition: scip_mem.h:105
static SCIP_DECL_HEURINITSOL(heurInitsolLpface)
Definition: heur_lpface.c:996
#define DEFAULT_LPLIMFAC
Definition: heur_lpface.c:81
SCIP_RETCODE SCIPsetHeurInitsol(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURINITSOL((*heurinitsol)))
Definition: scip_heur.c:226
SCIP_RETCODE SCIPsolve(SCIP *scip)
Definition: scip_solve.c:2624
const char * SCIPheurGetName(SCIP_HEUR *heur)
Definition: heur.c:1450
static SCIP_DECL_HEUREXEC(heurExecLpface)
Definition: heur_lpface.c:1072
#define SCIPerrorMessage
Definition: pub_message.h:64
SCIP_Bool SCIPisParamFixed(SCIP *scip, const char *name)
Definition: scip_param.c:219
SCIP_RETCODE SCIPaddCons(SCIP *scip, SCIP_CONS *cons)
Definition: scip_prob.c:2778
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)
public methods for event handler plugins and event handlers
SCIP_Bool SCIProwIsLocal(SCIP_ROW *row)
Definition: lp.c:17404
SCIP_RETCODE SCIPcopyVars(SCIP *sourcescip, SCIP *targetscip, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, SCIP_VAR **fixedvars, SCIP_Real *fixedvals, int nfixedvars, SCIP_Bool global)
Definition: scip_copy.c:1178
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 SCIPcopyCuts(SCIP *sourcescip, SCIP *targetscip, SCIP_HASHMAP *varmap, SCIP_HASHMAP *consmap, SCIP_Bool global, int *ncutsadded)
Definition: scip_copy.c:2125
BMS_BLKMEM * SCIPblkmem(SCIP *scip)
Definition: scip_mem.c:57
struct SCIP_EventData SCIP_EVENTDATA
Definition: type_event.h:173
#define DEFAULT_MINFIXINGRATE
Definition: heur_lpface.c:78
void SCIPhashmapFree(SCIP_HASHMAP **hashmap)
Definition: misc.c:3058
SCIP_RETCODE SCIPgetBoolParam(SCIP *scip, const char *name, SCIP_Bool *value)
Definition: scip_param.c:250
#define NULL
Definition: lpi_spx1.cpp:164
static void subscipdataReset(SUBSCIPDATA *subscipdata)
Definition: heur_lpface.c:543
#define REALABS(x)
Definition: def.h:210
SCIP_Real SCIPvarGetLPSol(SCIP_VAR *var)
Definition: var.c:18297
public methods for problem copies
public methods for primal CIP solutions
#define SCIP_CALL(x)
Definition: def.h:394
SCIP_Real SCIPgetLowerbound(SCIP *scip)
SCIP_Bool SCIPvarIsRelaxationOnly(SCIP_VAR *var)
Definition: var.c:17551
SCIP_Real SCIProwGetRhs(SCIP_ROW *row)
Definition: lp.c:17305
void SCIPverbMessage(SCIP *scip, SCIP_VERBLEVEL msgverblevel, FILE *file, const char *formatstr,...)
Definition: scip_message.c:225
#define DEFAULT_DUALBASISEQUATIONS
Definition: heur_lpface.c:88
SCIP_Longint SCIPheurGetNCalls(SCIP_HEUR *heur)
Definition: heur.c:1576
SCIP_RETCODE SCIPgetLongintParam(SCIP *scip, const char *name, SCIP_Longint *value)
Definition: scip_param.c:288
SCIP_COL ** SCIProwGetCols(SCIP_ROW *row)
Definition: lp.c:17241
public methods for primal heuristic plugins and divesets
public methods for constraint handler plugins and constraints
SCIP_RETCODE SCIPchgVarObj(SCIP *scip, SCIP_VAR *var, SCIP_Real newobj)
Definition: scip_var.c:4513
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:2960
static SCIP_RETCODE setupSubscipLpface(SCIP *scip, SCIP *subscip, SCIP_HEURDATA *heurdata, SCIP_VAR **subvars, SCIP_VAR **vars, SCIP_VAR **fixvars, SCIP_Real *fixvals, int nfixvars, int nvars)
Definition: heur_lpface.c:732
#define SCIPallocBufferArray(scip, ptr, num)
Definition: scip_mem.h:124
SCIP_Real * SCIProwGetVals(SCIP_ROW *row)
Definition: lp.c:17251
#define HEUR_FREQ
Definition: heur_lpface.c:70
SCIP * subscip
Definition: heur_lpface.c:104
public data structures and miscellaneous methods
#define DEFAULT_COPYCUTS
Definition: heur_lpface.c:85
#define SCIP_Bool
Definition: def.h:93
SCIP_RETCODE SCIPcatchEvent(SCIP *scip, SCIP_EVENTTYPE eventtype, SCIP_EVENTHDLR *eventhdlr, SCIP_EVENTDATA *eventdata, int *filterpos)
Definition: scip_event.c:286
static SCIP_DECL_HEURFREE(heurFreeLpface)
Definition: heur_lpface.c:950
SCIP_LPSOLSTAT SCIPgetLPSolstat(SCIP *scip)
Definition: scip_lp.c:168
static SCIP_RETCODE setSubscipParameters(SCIP *subscip)
Definition: heur_lpface.c:487
SCIP_EVENTTYPE SCIPeventGetType(SCIP_EVENT *event)
Definition: event.c:1030
enum SCIP_Status SCIP_STATUS
Definition: type_stat.h:67
static SCIP_RETCODE changeSubvariableObjective(SCIP *scip, SCIP *subscip, SCIP_VAR *var, SCIP_VAR *subvar, SCIP_HEURDATA *heurdata)
Definition: heur_lpface.c:642
int SCIPgetDepth(SCIP *scip)
Definition: scip_tree.c:670
#define MAX(x, y)
Definition: tclique_def.h:92
SCIP_RETCODE SCIPsetIntParam(SCIP *scip, const char *name, int value)
Definition: scip_param.c:487
public methods for LP management
SCIP_Real SCIPvarGetObj(SCIP_VAR *var)
Definition: var.c:17771
int SCIPgetNSols(SCIP *scip)
Definition: scip_sol.c:2214
#define HEUR_NAME
Definition: heur_lpface.c:66
static SCIP_RETCODE setSubscipLimits(SCIP *scip, SCIP *subscip, SCIP_HEUR *heur, SCIP_HEURDATA *heurdata, SCIP_Bool *success)
Definition: heur_lpface.c:429
SCIP_COL * SCIPvarGetCol(SCIP_VAR *var)
Definition: var.c:17634
Constraint handler for linear constraints in their most general form, .
int SCIPgetNObjVars(SCIP *scip)
Definition: scip_prob.c:2228
SCIP_Bool SCIPisInfinity(SCIP *scip, SCIP_Real val)
SCIP_Real objbound
Definition: heur_lpface.c:107
static SCIP_DECL_EVENTEXEC(eventExecLpface)
Definition: heur_lpface.c:707
public methods for the LP relaxation, rows and columns
SCIP_RETCODE SCIPsetCharParam(SCIP *scip, const char *name, char value)
Definition: scip_param.c:661
#define HEUR_DESC
Definition: heur_lpface.c:67
int SCIPgetNVars(SCIP *scip)
Definition: scip_prob.c:2000
static void updateFailureStatistic(SCIP *scip, SCIP_HEURDATA *heurdata)
Definition: heur_lpface.c:383
#define SCIP_REAL_MAX
Definition: def.h:187
SCIP_RETCODE SCIPcreateConsLinear(SCIP *scip, SCIP_CONS **cons, const char *name, int nvars, SCIP_VAR **vars, SCIP_Real *vals, SCIP_Real lhs, SCIP_Real rhs, 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_Real SCIProwGetConstant(SCIP_ROW *row)
Definition: lp.c:17261
public methods for branching rule plugins and branching
SCIP_Bool SCIPisObjIntegral(SCIP *scip)
Definition: scip_prob.c:1570
public methods for managing events
general public methods
SCIP_Real SCIPgetLPObjval(SCIP *scip)
Definition: scip_lp.c:247
SCIP_SOL * SCIPgetBestSol(SCIP *scip)
Definition: scip_sol.c:2313
SCIP_Bool SCIPisGT(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
SCIP_Bool SCIPisIntegral(SCIP *scip, SCIP_Real val)
SCIP_RETCODE SCIPaddCharParam(SCIP *scip, const char *name, const char *desc, char *valueptr, SCIP_Bool isadvanced, char defaultvalue, const char *allowedvalues, SCIP_DECL_PARAMCHGD((*paramchgd)), SCIP_PARAMDATA *paramdata)
Definition: scip_param.c:167
SCIP_VAR ** subvars
Definition: heur_lpface.c:105
SCIP_VAR * SCIPcolGetVar(SCIP_COL *col)
Definition: lp.c:17045
public methods for solutions
SCIP_Longint SCIPgetMemUsed(SCIP *scip)
Definition: scip_mem.c:100
static SCIP_RETCODE setupSubproblem(SCIP *scip, SCIP *subscip, SCIP_VAR **subvars, SCIP_HEURDATA *heurdata)
Definition: heur_lpface.c:334
SCIP_RETCODE SCIPreleaseCons(SCIP *scip, SCIP_CONS **cons)
Definition: scip_cons.c:1119
#define SCIP_DECL_HEUREXIT(x)
Definition: type_heur.h:120
public methods for message output
#define DEFAULT_MINPATHLEN
Definition: heur_lpface.c:90
SCIP_RETCODE SCIPsetHeurInit(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURINIT((*heurinit)))
Definition: scip_heur.c:194
SCIP_Real SCIPretransformObj(SCIP *scip, SCIP_Real obj)
Definition: scip_sol.c:1576
SCIP_Longint SCIPgetMemExternEstim(SCIP *scip)
Definition: scip_mem.c:126
SCIP_NODESEL * SCIPfindNodesel(SCIP *scip, const char *name)
Definition: scip_nodesel.c:234
#define HEUR_TIMING
Definition: heur_lpface.c:73
SCIP_VAR ** SCIPgetVars(SCIP *scip)
Definition: scip_prob.c:1955
SCIP_VARSTATUS SCIPvarGetStatus(SCIP_VAR *var)
Definition: var.c:17383
#define EVENTHDLR_NAME
Definition: heur_lpface.c:94
#define SCIP_Real
Definition: def.h:186
static SCIP_RETCODE solveSubscipLpface(SCIP *scip, SCIP *subscip, SCIP_HEUR *heur, SCIP_HEURDATA *heurdata, SCIP_VAR **subvars, SCIP_RESULT *result, SCIP_Real focusnodelb, SCIP_Bool *keepthisscip)
Definition: heur_lpface.c:816
SCIP_Bool SCIPisStopped(SCIP *scip)
Definition: scip_general.c:703
public methods for message handling
#define SCIP_INVALID
Definition: def.h:206
#define HEUR_USESSUBSCIP
Definition: heur_lpface.c:74
#define SCIP_Longint
Definition: def.h:171
SCIP_Bool SCIPallColsInLP(SCIP *scip)
Definition: scip_lp.c:649
SCIP_Real SCIPfrac(SCIP *scip, SCIP_Real val)
static SCIP_RETCODE subscipdataCopySubscip(SCIP *scip, SUBSCIPDATA *subscipdata, SCIP *subscip, SCIP_VAR **subvars, int nvars)
Definition: heur_lpface.c:584
SCIP_Real SCIPgetNodeLowerbound(SCIP *scip, SCIP_NODE *node)
Definition: scip_prob.c:3630
SCIP_RETCODE SCIPtransformProb(SCIP *scip)
Definition: scip_solve.c:367
SCIP_Bool SCIPisZero(SCIP *scip, SCIP_Real val)
SCIP_Bool SCIPisLE(SCIP *scip, SCIP_Real val1, SCIP_Real val2)
SCIP_RETCODE SCIPsetHeurCopy(SCIP *scip, SCIP_HEUR *heur, SCIP_DECL_HEURCOPY((*heurcopy)))
Definition: scip_heur.c:162
SCIP_RETCODE SCIPwriteParams(SCIP *scip, const char *filename, SCIP_Bool comments, SCIP_Bool onlychanged)
Definition: scip_param.c:792
SCIP_RETCODE SCIPinterruptSolve(SCIP *scip)
Definition: scip_solve.c:3553
public methods for primal heuristics
SCIP_RETCODE SCIPgetLPRowsData(SCIP *scip, SCIP_ROW ***rows, int *nrows)
Definition: scip_lp.c:570
#define SCIP_CALL_ABORT(x)
Definition: def.h:373
SCIP_HEURDATA * SCIPheurGetData(SCIP_HEUR *heur)
Definition: heur.c:1361
static SCIP_DECL_HEURINIT(heurInitLpface)
Definition: heur_lpface.c:970
SCIP_Longint SCIPgetNNodes(SCIP *scip)
SCIP_Longint SCIPgetNLPs(SCIP *scip)
public methods for global and local (sub)problems
SCIP_Bool SCIPvarIsIntegral(SCIP_VAR *var)
Definition: var.c:17455
#define DEFAULT_MINNODES
Definition: heur_lpface.c:77
SCIP_Real SCIPgetSolVal(SCIP *scip, SCIP_SOL *sol, SCIP_VAR *var)
Definition: scip_sol.c:1361
default SCIP plugins
int SCIPsolGetIndex(SCIP_SOL *sol)
Definition: sol.c:2644
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
SCIP_RETCODE SCIPsetSubscipsOff(SCIP *scip, SCIP_Bool quiet)
Definition: scip_param.c:883
SCIP_RETCODE SCIPsetLongintParam(SCIP *scip, const char *name, SCIP_Longint value)
Definition: scip_param.c:545
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
LNS heuristic that tries to compute integral solution on optimal LP face.
SCIP_Real SCIPgetRowActivity(SCIP *scip, SCIP_ROW *row)
Definition: scip_lp.c:2101
SCIP_RETCODE SCIPfree(SCIP **scip)
Definition: scip_general.c:324
static SCIP_DECL_HEURCOPY(heurCopyLpface)
Definition: heur_lpface.c:936
memory allocation routines