/** creates a new node entry in the VBC output file */
SCIP_RETCODE SCIPvbcNewChild(
SCIP_VBC* vbc, /**< VBC information */
SCIP_STAT* stat, /**< problem statistics */
SCIP_NODE* node /**< new node, that was created */
)
{
SCIP_VAR* branchvar;
SCIP_BOUNDTYPE branchtype;
SCIP_Real branchbound;
size_t parentnodenum;
size_t nodenum;
assert(vbc != NULL);
assert(stat != NULL);
assert(node != NULL);
/* check, if VBC output should be created */
if( vbc->file == NULL )
return SCIP_OKAY;
/* vbc is disabled on probing nodes */
if( SCIPnodeGetType(node) == SCIP_NODETYPE_PROBINGNODE )
return SCIP_OKAY;
/* insert mapping node -> nodenum into hash map */
if( stat->ncreatednodesrun >= (SCIP_Longint)INT_MAX )
{
SCIPerrorMessage("too many nodes to store in the VBC file\n");
return SCIP_INVALIDDATA;
}
nodenum = (size_t)stat->ncreatednodesrun;
assert(nodenum > 0);
SCIP_CALL( SCIPhashmapInsert(vbc->nodenum, node, (void*)nodenum) );
/* get nodenum of parent node from hash map */
parentnodenum = (node->parent != NULL ? (size_t)SCIPhashmapGetImage(vbc->nodenum, node->parent) : 0);
assert(node->parent == NULL || parentnodenum > 0);
/* get branching information */
getBranchInfo(node, &branchvar, &branchtype, &branchbound);
printTime(vbc, stat);
SCIPmessageFPrintInfo(vbc->messagehdlr, vbc->file, "N %d %d %d\n", (int)parentnodenum, (int)nodenum, SCIP_VBCCOLOR_UNSOLVED);
printTime(vbc, stat);
if( branchvar != NULL )
{
SCIPmessageFPrintInfo(vbc->messagehdlr, vbc->file, "I %d \\inode:\\t%d (%p)\\idepth:\\t%d\\nvar:\\t%s [%g,%g] %s %f\\nbound:\\t%f\n",
(int)nodenum, (int)nodenum, node, SCIPnodeGetDepth(node),
SCIPvarGetName(branchvar), SCIPvarGetLbLocal(branchvar), SCIPvarGetUbLocal(branchvar),
branchtype == SCIP_BOUNDTYPE_LOWER ? ">=" : "<=", branchbound, SCIPnodeGetLowerbound(node));
}
else
{
SCIPmessageFPrintInfo(vbc->messagehdlr, vbc->file, "I %d \\inode:\\t%d (%p)\\idepth:\\t%d\\nvar:\\t-\\nbound:\\t%f\n",
(int)nodenum, (int)nodenum, node, SCIPnodeGetDepth(node), SCIPnodeGetLowerbound(node));
}
return SCIP_OKAY;
}
/** fills the whole Decomp struct after the dec file has been read */
static
SCIP_RETCODE fillDecompStruct(
SCIP* scip, /**< SCIP data structure */
DECINPUT* decinput, /**< DEC reading data */
DEC_DECOMP* decomp, /**< DEC_DECOMP structure to fill */
SCIP_READERDATA* readerdata /**< reader data*/
)
{
SCIP_HASHMAP* constoblock;
SCIP_CONS** allcons;
int i;
int j;
int nblockconss;
int nconss;
int nblocks;
SCIP_Bool valid;
assert(scip != NULL);
assert(decinput != NULL);
assert(decomp != NULL);
assert(readerdata != NULL);
valid = FALSE;
allcons = SCIPgetConss(scip);
nconss = SCIPgetNConss(scip);
nblocks = decinput->nblocks;
DECdecompSetPresolved(decomp, decinput->presolved);
DECdecompSetNBlocks(decomp, nblocks);
DECdecompSetDetector(decomp, NULL);
DECdecompSetType(decomp, DEC_DECTYPE_ARROWHEAD, &valid);
assert(valid);
/* hashmaps */
SCIP_CALL( SCIPhashmapCreate(&constoblock, SCIPblkmem(scip), nconss) );
for( i = 0; i < nconss; i ++ )
{
SCIP_CALL( SCIPhashmapInsert(constoblock, allcons[i], (void*) (size_t) (nblocks+1)) );
}
for( i = 0; i < nblocks; i ++ )
{
nblockconss = readerdata->nblockconss[i];
for( j = 0; j < nblockconss; j ++ )
{
/* hashmap */
SCIPdebugMessage("cons %s is in block %d\n", SCIPconsGetName(readerdata->blockconss[i][j]), i);
SCIP_CALL( SCIPhashmapSetImage(constoblock, readerdata->blockconss[i][j], (void*) (size_t) (i+1)) );
}
}
SCIP_CALL( DECfilloutDecdecompFromConstoblock(scip, decomp, constoblock, nblocks, SCIPgetVars(scip), SCIPgetNVars(scip), SCIPgetConss(scip), SCIPgetNConss(scip), FALSE) );
return SCIP_OKAY;
}
/** reads an BLK file */
static
SCIP_RETCODE readBLKFile(
SCIP* scip, /**< SCIP data structure */
SCIP_READER* reader, /**< reader data structure */
BLKINPUT* blkinput, /**< BLK reading data */
const char* filename /**< name of the input file */
)
{
DEC_DECOMP *decdecomp;
int i;
int nconss;
int nblocksread;
int nvars;
SCIP_READERDATA* readerdata;
SCIP_CONS** conss;
nblocksread = FALSE;
assert(scip != NULL);
assert(reader != NULL);
assert(blkinput != NULL);
if( SCIPgetStage(scip) < SCIP_STAGE_TRANSFORMED )
SCIP_CALL( SCIPtransformProb(scip) );
readerdata = SCIPreaderGetData(reader);
assert(readerdata != NULL);
readerdata->nlinkingcons = SCIPgetNConss(scip);
readerdata->nlinkingvars = 0;
nvars = SCIPgetNVars(scip);
conss = SCIPgetConss(scip);
nconss = SCIPgetNConss(scip);
/* alloc: var -> block mapping */
SCIP_CALL( SCIPallocMemoryArray(scip, &readerdata->varstoblock, nvars) );
for( i = 0; i < nvars; i ++ )
{
readerdata->varstoblock[i] = NOVALUE;
}
/* alloc: linkingvar -> blocks mapping */
SCIP_CALL( SCIPallocMemoryArray(scip, &readerdata->linkingvarsblocks, nvars) );
SCIP_CALL( SCIPallocMemoryArray(scip, &readerdata->nlinkingvarsblocks, nvars) );
BMSclearMemoryArray(readerdata->linkingvarsblocks, nvars);
BMSclearMemoryArray(readerdata->nlinkingvarsblocks, nvars);
/* cons -> block mapping */
SCIP_CALL( SCIPhashmapCreate(&readerdata->constoblock, SCIPblkmem(scip), nconss) );
for( i = 0; i < SCIPgetNConss(scip); i ++ )
{
SCIP_CALL( SCIPhashmapInsert(readerdata->constoblock, conss[i], (void*)(size_t) NOVALUE) );
}
/* open file */
blkinput->file = SCIPfopen(filename, "r");
if( blkinput->file == NULL )
{
SCIPerrorMessage("cannot open file <%s> for reading\n", filename);
SCIPprintSysError(filename);
return SCIP_NOFILE;
}
/* parse the file */
blkinput->section = BLK_START;
while( blkinput->section != BLK_END && !hasError(blkinput) )
{
switch( blkinput->section )
{
case BLK_START:
SCIP_CALL( readStart(scip, blkinput) );
break;
case BLK_PRESOLVED:
SCIP_CALL( readPresolved(scip, blkinput) );
if( blkinput->presolved && SCIPgetStage(scip) < SCIP_STAGE_PRESOLVED )
{
assert(blkinput->haspresolvesection);
/** @bug GCG should be able to presolve the problem first */
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, "decomposition belongs to the presolved problem, please presolve the problem first.\n");
goto TERMINATE;
}
break;
case BLK_NBLOCKS:
SCIP_CALL( readNBlocks(scip, blkinput) );
if( blkinput->haspresolvesection && !blkinput->presolved && SCIPgetStage(scip) >= SCIP_STAGE_PRESOLVED )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, "decomposition belongs to the unpresolved problem, please re-read the problem and read the decomposition without presolving.\n");
goto TERMINATE;
}
if( !blkinput->haspresolvesection )
{
SCIPwarningMessage(scip, "decomposition has no presolve section at beginning. The behaviour is undefined. See the FAQ for further information.\n");
}
break;
case BLK_BLOCK:
if( nblocksread == FALSE )
{
/* alloc n vars per block */
SCIP_CALL( SCIPallocMemoryArray(scip, &readerdata->nblockvars, blkinput->nblocks) );
SCIP_CALL( SCIPallocMemoryArray(scip, &readerdata->nblockcons, blkinput->nblocks) );
SCIP_CALL( SCIPallocMemoryArray(scip, &readerdata->blockcons, blkinput->nblocks) );
for( i = 0; i < blkinput->nblocks; ++i )
{
readerdata->nblockvars[i] = 0;
readerdata->nblockcons[i] = 0;
SCIP_CALL( SCIPallocMemoryArray(scip, &(readerdata->blockcons[i]), nconss) ); /*lint !e866*/
}
nblocksread = TRUE;
}
SCIP_CALL( readBlock(scip, blkinput, readerdata) );
break;
case BLK_MASTERCONSS:
SCIP_CALL( readMasterconss(scip, blkinput, readerdata) );
break;
case BLK_END: /* this is already handled in the while() loop */
default:
SCIPerrorMessage("invalid BLK file section <%d>\n", blkinput->section);
return SCIP_INVALIDDATA;
}
}
SCIP_CALL( DECdecompCreate(scip, &decdecomp) );
/* fill decomp */
SCIP_CALL( fillDecompStruct(scip, blkinput, decdecomp, readerdata) );
/* add decomp to cons_decomp */
SCIP_CALL( SCIPconshdlrDecompAddDecdecomp(scip, decdecomp) );
for( i = 0; i < nvars; ++i )
{
assert(readerdata->linkingvarsblocks[i] != NULL || readerdata->nlinkingvarsblocks[i] == 0);
if( readerdata->nlinkingvarsblocks[i] > 0 )
{
SCIPfreeMemoryArray(scip, &readerdata->linkingvarsblocks[i]);
}
}
TERMINATE:
if( nblocksread )
{
for( i = blkinput->nblocks - 1; i >= 0; --i )
{
SCIPfreeMemoryArray(scip, &(readerdata->blockcons[i]));
}
SCIPfreeMemoryArray(scip, &readerdata->blockcons);
SCIPfreeMemoryArray(scip, &readerdata->nblockcons);
SCIPfreeMemoryArray(scip, &readerdata->nblockvars);
}
SCIPhashmapFree(&readerdata->constoblock);
SCIPfreeMemoryArray(scip, &readerdata->nlinkingvarsblocks);
SCIPfreeMemoryArray(scip, &readerdata->linkingvarsblocks);
SCIPfreeMemoryArray(scip, &readerdata->varstoblock);
/* close file */
SCIPfclose(blkinput->file);
return SCIP_OKAY;
}
/** fills the whole Decomp struct after the blk file has been read */
static
SCIP_RETCODE fillDecompStruct(
SCIP* scip, /**< SCIP data structure */
BLKINPUT* blkinput, /**< blk reading data */
DEC_DECOMP* decomp, /**< DEC_DECOMP structure to fill */
SCIP_READERDATA* readerdata /**< reader data*/
)
{
SCIP_HASHMAP* constoblock;
SCIP_CONS** allcons;
SCIP_VAR** consvars;
int i;
int j;
int nvars;
int blocknr;
int nconss;
int nblocks;
SCIP_Bool valid;
assert(scip != NULL);
assert(blkinput != NULL);
assert(readerdata != NULL);
allcons = SCIPgetConss(scip);
nvars = SCIPgetNVars(scip);
nconss = SCIPgetNConss(scip);
nblocks = blkinput->nblocks;
DECdecompSetPresolved(decomp, blkinput->presolved);
DECdecompSetNBlocks(decomp, nblocks);
DECdecompSetDetector(decomp, NULL);
DECdecompSetType(decomp, DEC_DECTYPE_ARROWHEAD, &valid);
assert(valid);
/* hashmaps */
SCIP_CALL( SCIPhashmapCreate(&constoblock, SCIPblkmem(scip), nconss) );
SCIP_CALL( SCIPallocMemoryArray(scip, &consvars, nvars) );
/* assign constraints to blocks or declare them linking */
for( i = 0; i < nconss; i ++ )
{
SCIP_CONS* cons;
cons = allcons[i];
if( SCIPhashmapGetImage(readerdata->constoblock, cons) == (void*) (size_t) LINKINGVALUE )
{
SCIP_CALL( SCIPhashmapInsert(constoblock, cons, (void*) (size_t) (nblocks+1)) );
SCIPdebugMessage("cons %s is linking\n", SCIPconsGetName(cons));
}
/* check whether all variables in the constraint belong to one block */
else
{
int nconsvars;
nconsvars = SCIPgetNVarsXXX(scip, cons);
assert(nconsvars < nvars);
SCIP_CALL( SCIPgetVarsXXX(scip, cons, consvars, nvars) );
blocknr = -1;
/* find the first unique assignment of a contained variable to a block */
for( j = 0; j < nconsvars; ++j )
{
/* if a contained variables is directly transferred to the master, the constraint is a linking constraint */
if( readerdata->varstoblock[SCIPvarGetProbindex(consvars[j])] == NOVALUE )
{
blocknr = -1;
break;
}
/* assign the constraint temporarily to the block of the variable, if it is unique */
if( blocknr == -1 && readerdata->varstoblock[SCIPvarGetProbindex(consvars[j])] != LINKINGVALUE )
{
blocknr = readerdata->varstoblock[SCIPvarGetProbindex(consvars[j])];
}
}
if( blocknr != -1 )
{
int varidx;
int varblock;
/* check whether all contained variables are copied into the assigned block;
* if not, the constraint is treated as a linking constraint
*/
for( j = 0; j < nconsvars; ++j )
{
varidx = SCIPvarGetProbindex(consvars[j]);
varblock = readerdata->varstoblock[varidx];
assert(varblock != NOVALUE);
if( varblock != LINKINGVALUE && varblock != blocknr )
{
blocknr = -1;
break;
}
else if( varblock == LINKINGVALUE )
{
int k;
for( k = 0; k < readerdata->nlinkingvarsblocks[varidx]; ++k )
{
if( readerdata->linkingvarsblocks[varidx][k] == blocknr )
break;
}
/* we did not break, so the variable is not assigned to the block */
if( k == readerdata->nlinkingvarsblocks[varidx] )
{
blocknr = -1;
break;
}
}
}
}
if( blocknr == -1 )
{
SCIP_CALL( SCIPhashmapInsert(constoblock, cons, (void*) (size_t) (nblocks+1)) );
SCIPdebugMessage("constraint <%s> is a linking constraint\n",
SCIPconsGetName(cons));
}
else
{
SCIP_CALL( SCIPhashmapInsert(constoblock, cons, (void*) (size_t) (blocknr+1)) );
SCIPdebugMessage("constraint <%s> is assigned to block %d\n", SCIPconsGetName(cons), blocknr);
}
}
}
SCIP_CALL( DECfilloutDecdecompFromConstoblock(scip, decomp, constoblock, nblocks, SCIPgetVars(scip), SCIPgetNVars(scip), SCIPgetConss(scip), SCIPgetNConss(scip), FALSE) );
SCIPfreeMemoryArray(scip, &consvars);
return SCIP_OKAY;
}
/** creates a new node entry in the visualization output file */
SCIP_RETCODE SCIPvisualNewChild(
SCIP_VISUAL* visual, /**< visualization information */
SCIP_SET* set, /**< global SCIP settings */
SCIP_STAT* stat, /**< problem statistics */
SCIP_NODE* node /**< new node, that was created */
)
{
SCIP_VAR* branchvar;
SCIP_BOUNDTYPE branchtype;
SCIP_Real branchbound;
SCIP_Real lowerbound;
size_t parentnodenum;
size_t nodenum;
assert( visual != NULL );
assert( stat != NULL );
assert( node != NULL );
/* visualization is disabled on probing nodes */
if( SCIPnodeGetType(node) == SCIP_NODETYPE_PROBINGNODE )
return SCIP_OKAY;
/* check whether output should be created */
if ( visual->vbcfile == NULL && visual->bakfile == NULL )
return SCIP_OKAY;
/* insert mapping node -> nodenum into hash map */
if( stat->ncreatednodesrun >= (SCIP_Longint)INT_MAX )
{
SCIPerrorMessage("too many nodes to store in the visualization file\n");
return SCIP_INVALIDDATA;
}
nodenum = (size_t)stat->ncreatednodesrun;
assert(nodenum > 0);
SCIP_CALL( SCIPhashmapInsert(visual->nodenum, node, (void*)nodenum) );
/* get nodenum of parent node from hash map */
parentnodenum = (node->parent != NULL ? (size_t)SCIPhashmapGetImage(visual->nodenum, node->parent) : 0);
assert(node->parent == NULL || parentnodenum > 0);
/* get branching information */
getBranchInfo(node, &branchvar, &branchtype, &branchbound);
/* determine lower bound */
if ( set->visual_objextern )
lowerbound = SCIPretransformObj(set->scip, SCIPnodeGetLowerbound(node));
else
lowerbound = SCIPnodeGetLowerbound(node);
if ( visual->vbcfile != NULL )
{
printTime(visual, stat, TRUE);
SCIPmessageFPrintInfo(visual->messagehdlr, visual->vbcfile, "N %d %d %d\n", (int)parentnodenum, (int)nodenum, SCIP_VBCCOLOR_UNSOLVED);
printTime(visual, stat, TRUE);
if( branchvar != NULL )
{
SCIPmessageFPrintInfo(visual->messagehdlr, visual->vbcfile, "I %d \\inode:\\t%d (%p)\\idepth:\\t%d\\nvar:\\t%s [%g,%g] %s %f\\nbound:\\t%f\n",
(int)nodenum, (int)nodenum, node, SCIPnodeGetDepth(node),
SCIPvarGetName(branchvar), SCIPvarGetLbLocal(branchvar), SCIPvarGetUbLocal(branchvar),
branchtype == SCIP_BOUNDTYPE_LOWER ? ">=" : "<=", branchbound, lowerbound);
}
else
{
SCIPmessageFPrintInfo(visual->messagehdlr, visual->vbcfile, "I %d \\inode:\\t%d (%p)\\idepth:\\t%d\\nvar:\\t-\\nbound:\\t%f\n",
(int)nodenum, (int)nodenum, node, SCIPnodeGetDepth(node), lowerbound);
}
}
/* For BAK, not all available information is available here. Use SCIPvisualUpdateChild() instead */
return SCIP_OKAY;
}
/** LP solution separation method of separator */
static
SCIP_DECL_SEPAEXECLP(sepaExeclpRapidlearning)
{/*lint --e{715}*/
SCIP* subscip; /* the subproblem created by rapid learning */
SCIP_SEPADATA* sepadata; /* separator's private data */
SCIP_VAR** vars; /* original problem's variables */
SCIP_VAR** subvars; /* subproblem's variables */
SCIP_HASHMAP* varmapfw; /* mapping of SCIP variables to sub-SCIP variables */
SCIP_HASHMAP* varmapbw; /* mapping of sub-SCIP variables to SCIP variables */
SCIP_CONSHDLR** conshdlrs; /* array of constraint handler's that might that might obtain conflicts */
int* oldnconss; /* number of constraints without rapid learning conflicts */
SCIP_Longint nodelimit; /* node limit for the subproblem */
SCIP_Real timelimit; /* time limit for the subproblem */
SCIP_Real memorylimit; /* memory limit for the subproblem */
int nconshdlrs; /* size of conshdlr and oldnconss array */
int nfixedvars; /* number of variables that could be fixed by rapid learning */
int nvars; /* number of variables */
int restartnum; /* maximal number of conflicts that should be created */
int i; /* counter */
SCIP_Bool success; /* was problem creation / copying constraint successful? */
SCIP_RETCODE retcode; /* used for catching sub-SCIP errors in debug mode */
int nconflicts; /* statistic: number of conflicts applied */
int nbdchgs; /* statistic: number of bound changes applied */
int n1startinfers; /* statistic: number of one side infer values */
int n2startinfers; /* statistic: number of both side infer values */
SCIP_Bool soladded; /* statistic: was a new incumbent found? */
SCIP_Bool dualboundchg; /* statistic: was a new dual bound found? */
SCIP_Bool disabledualreductions; /* TRUE, if dual reductions in sub-SCIP are not valid for original SCIP,
* e.g., because a constraint could not be copied or a primal solution
* could not be copied back
*/
int ndiscvars;
soladded = FALSE;
assert(sepa != NULL);
assert(scip != NULL);
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
ndiscvars = SCIPgetNBinVars(scip) + SCIPgetNIntVars(scip)+SCIPgetNImplVars(scip);
/* only run when still not fixed binary variables exists */
if( ndiscvars == 0 )
return SCIP_OKAY;
/* get separator's data */
sepadata = SCIPsepaGetData(sepa);
assert(sepadata != NULL);
/* only run for integer programs */
if( !sepadata->contvars && ndiscvars != SCIPgetNVars(scip) )
return SCIP_OKAY;
/* only run if there are few enough continuous variables */
if( sepadata->contvars && SCIPgetNContVars(scip) > sepadata->contvarsquot * SCIPgetNVars(scip) )
return SCIP_OKAY;
/* do not run if pricers are present */
if( SCIPgetNActivePricers(scip) > 0 )
return SCIP_OKAY;
/* if the separator should be exclusive to the root node, this prevents multiple calls due to restarts */
if( SCIPsepaGetFreq(sepa) == 0 && SCIPsepaGetNCalls(sepa) > 0)
return SCIP_OKAY;
/* call separator at most once per node */
if( SCIPsepaGetNCallsAtNode(sepa) > 0 )
return SCIP_OKAY;
/* do not call rapid learning, if the problem is too big */
if( SCIPgetNVars(scip) > sepadata->maxnvars || SCIPgetNConss(scip) > sepadata->maxnconss )
return SCIP_OKAY;
if( SCIPisStopped(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) );
/* initializing the subproblem */
SCIP_CALL( SCIPallocBufferArray(scip, &subvars, nvars) );
SCIP_CALL( SCIPcreate(&subscip) );
SCIP_CALL( SCIPhashmapCreate(&varmapfw, SCIPblkmem(subscip), SCIPcalcHashtableSize(5 * nvars)) );
success = FALSE;
/* copy the subproblem */
SCIP_CALL( SCIPcopy(scip, subscip, varmapfw, NULL, "rapid", FALSE, FALSE, &success) );
if( sepadata->copycuts )
{
/** copies all active cuts from cutpool of sourcescip to linear constraints in targetscip */
SCIP_CALL( SCIPcopyCuts(scip, subscip, varmapfw, NULL, FALSE) );
}
for( i = 0; i < nvars; i++ )
subvars[i] = (SCIP_VAR*) (size_t) SCIPhashmapGetImage(varmapfw, vars[i]);
SCIPhashmapFree(&varmapfw);
/* this avoids dual presolving */
if( !success )
{
for( i = 0; i < nvars; i++ )
{
SCIP_CALL( SCIPaddVarLocks(subscip, subvars[i], 1, 1 ) );
}
}
SCIPdebugMessage("Copying SCIP was%s successful.\n", success ? "" : " not");
/* mimic an FD solver: DFS, no LP solving, 1-FUIP instead of all-FUIP */
SCIP_CALL( SCIPsetIntParam(subscip, "lp/solvefreq", -1) );
SCIP_CALL( SCIPsetIntParam(subscip, "conflict/fuiplevels", 1) );
SCIP_CALL( SCIPsetIntParam(subscip, "nodeselection/dfs/stdpriority", INT_MAX/4) );
SCIP_CALL( SCIPsetBoolParam(subscip, "constraints/disableenfops", TRUE) );
SCIP_CALL( SCIPsetIntParam(subscip, "propagating/pseudoobj/freq", -1) );
/* use inference branching */
SCIP_CALL( SCIPsetBoolParam(subscip, "branching/inference/useweightedsum", FALSE) );
/* only create short conflicts */
SCIP_CALL( SCIPsetRealParam(subscip, "conflict/maxvarsfac", 0.05) );
/* set limits for the subproblem */
nodelimit = SCIPgetNLPIterations(scip);
nodelimit = MAX(sepadata->minnodes, nodelimit);
nodelimit = MIN(sepadata->maxnodes, nodelimit);
restartnum = 1000;
/* check whether there is enough time and memory left */
SCIP_CALL( SCIPgetRealParam(scip, "limits/time", &timelimit) );
if( !SCIPisInfinity(scip, timelimit) )
timelimit -= SCIPgetSolvingTime(scip);
SCIP_CALL( SCIPgetRealParam(scip, "limits/memory", &memorylimit) );
if( !SCIPisInfinity(scip, memorylimit) )
memorylimit -= SCIPgetMemUsed(scip)/1048576.0;
if( timelimit <= 0.0 || memorylimit <= 0.0 )
goto TERMINATE;
SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nodelimit/5) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/memory", memorylimit) );
SCIP_CALL( SCIPsetIntParam(subscip, "limits/restarts", 0) );
SCIP_CALL( SCIPsetIntParam(subscip, "conflict/restartnum", restartnum) );
/* forbid recursive call of heuristics and separators solving subMIPs */
SCIP_CALL( SCIPsetSubscipsOff(subscip, TRUE) );
/* disable cutting plane separation */
SCIP_CALL( SCIPsetSeparating(subscip, SCIP_PARAMSETTING_OFF, TRUE) );
/* disable expensive presolving */
SCIP_CALL( SCIPsetPresolving(subscip, SCIP_PARAMSETTING_FAST, TRUE) );
/* do not abort subproblem on CTRL-C */
SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) );
#ifndef SCIP_DEBUG
/* disable output to console */
SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) );
#endif
/* add an objective cutoff */
SCIP_CALL( SCIPsetObjlimit(subscip, SCIPgetUpperbound(scip)) );
/* create the variable mapping hash map */
SCIP_CALL( SCIPhashmapCreate(&varmapbw, SCIPblkmem(scip), SCIPcalcHashtableSize(5 * nvars)) );
/* store reversing mapping of variables */
SCIP_CALL( SCIPtransformProb(subscip) );
for( i = 0; i < nvars; ++i)
{
SCIP_CALL( SCIPhashmapInsert(varmapbw, SCIPvarGetTransVar(subvars[i]), vars[i]) );
}
/** allocate memory for constraints storage. Each constraint that will be created from now on will be a conflict.
* Therefore, we need to remember oldnconss to get the conflicts from the FD search.
*/
nconshdlrs = 4;
SCIP_CALL( SCIPallocBufferArray(scip, &conshdlrs, nconshdlrs) );
SCIP_CALL( SCIPallocBufferArray(scip, &oldnconss, nconshdlrs) );
/* store number of constraints before rapid learning search */
conshdlrs[0] = SCIPfindConshdlr(subscip, "bounddisjunction");
conshdlrs[1] = SCIPfindConshdlr(subscip, "setppc");
conshdlrs[2] = SCIPfindConshdlr(subscip, "linear");
conshdlrs[3] = SCIPfindConshdlr(subscip, "logicor");
/* redundant constraints might be eliminated in presolving */
SCIP_CALL( SCIPpresolve(subscip));
for( i = 0; i < nconshdlrs; ++i)
{
if( conshdlrs[i] != NULL )
oldnconss[i] = SCIPconshdlrGetNConss(conshdlrs[i]);
}
nfixedvars = SCIPgetNFixedVars(scip);
/* solve the subproblem */
retcode = SCIPsolve(subscip);
/* Errors in solving the subproblem should not kill the overall solving process
* Hence, the return code is caught and a warning is printed, only in debug mode, SCIP will stop.
*/
if( retcode != SCIP_OKAY )
{
#ifndef NDEBUG
SCIP_CALL( retcode );
#endif
SCIPwarningMessage("Error while solving subproblem in rapid learning separator; sub-SCIP terminated with code <%d>\n",retcode);
}
/* abort solving, if limit of applied conflicts is reached */
if( SCIPgetNConflictConssApplied(subscip) >= restartnum )
{
SCIPdebugMessage("finish after %lld successful conflict calls.\n", SCIPgetNConflictConssApplied(subscip));
}
/* if the first 20% of the solution process were successful, proceed */
else if( (sepadata->applyprimalsol && SCIPgetNSols(subscip) > 0 && SCIPisFeasLT(scip, SCIPgetUpperbound(subscip), SCIPgetUpperbound(scip) ) )
|| (sepadata->applybdchgs && SCIPgetNFixedVars(subscip) > nfixedvars)
|| (sepadata->applyconflicts && SCIPgetNConflictConssApplied(subscip) > 0) )
{
SCIPdebugMessage("proceed solving after the first 20%% of the solution process, since:\n");
if( SCIPgetNSols(subscip) > 0 && SCIPisFeasLE(scip, SCIPgetUpperbound(subscip), SCIPgetUpperbound(scip) ) )
{
SCIPdebugMessage(" - there was a better solution (%f < %f)\n",SCIPgetUpperbound(subscip), SCIPgetUpperbound(scip));
}
if( SCIPgetNFixedVars(subscip) > nfixedvars )
{
SCIPdebugMessage(" - there were %d variables fixed\n", SCIPgetNFixedVars(scip)-nfixedvars );
}
if( SCIPgetNConflictConssFound(subscip) > 0 )
{
SCIPdebugMessage(" - there were %lld conflict constraints created\n", SCIPgetNConflictConssApplied(subscip));
}
/* set node limit to 100% */
SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nodelimit) );
/* solve the subproblem */
retcode = SCIPsolve(subscip);
/* Errors in solving the subproblem should not kill the overall solving process
* Hence, the return code is caught and a warning is printed, only in debug mode, SCIP will stop.
*/
if( retcode != SCIP_OKAY )
{
#ifndef NDEBUG
SCIP_CALL( retcode );
#endif
SCIPwarningMessage("Error while solving subproblem in rapid learning separator; sub-SCIP terminated with code <%d>\n",retcode);
}
}
else
{
SCIPdebugMessage("do not proceed solving after the first 20%% of the solution process.\n");
}
#ifdef SCIP_DEBUG
SCIP_CALL( SCIPprintStatistics(subscip, NULL) );
#endif
disabledualreductions = FALSE;
/* check, whether a solution was found */
if( sepadata->applyprimalsol && SCIPgetNSols(subscip) > 0 && SCIPfindHeur(scip, "trysol") != NULL )
{
SCIP_HEUR* heurtrysol;
SCIP_SOL** subsols;
int nsubsols;
/* check, whether a solution was found;
* due to numerics, it might happen that not all solutions are feasible -> try all solutions until was declared to be feasible
*/
nsubsols = SCIPgetNSols(subscip);
subsols = SCIPgetSols(subscip);
soladded = FALSE;
heurtrysol = SCIPfindHeur(scip, "trysol");
/* sequentially add solutions to trysol heuristic */
for( i = 0; i < nsubsols && !soladded; ++i )
{
SCIPdebugMessage("Try to create new solution by copying subscip solution.\n");
SCIP_CALL( createNewSol(scip, subscip, subvars, heurtrysol, subsols[i], &soladded) );
}
if( !soladded || !SCIPisEQ(scip, SCIPgetSolOrigObj(subscip, subsols[i-1]), SCIPgetSolOrigObj(subscip, subsols[0])) )
disabledualreductions = TRUE;
}
/* if the sub problem was solved completely, we update the dual bound */
dualboundchg = FALSE;
if( sepadata->applysolved && !disabledualreductions
&& (SCIPgetStatus(subscip) == SCIP_STATUS_OPTIMAL || SCIPgetStatus(subscip) == SCIP_STATUS_INFEASIBLE) )
{
/* we need to multiply the dualbound with the scaling factor and add the offset,
* because this information has been disregarded in the sub-SCIP */
SCIPdebugMessage("Update old dualbound %g to new dualbound %g.\n", SCIPgetDualbound(scip), SCIPgetTransObjscale(scip) * SCIPgetDualbound(subscip) + SCIPgetTransObjoffset(scip));
SCIP_CALL( SCIPupdateLocalDualbound(scip, SCIPgetDualbound(subscip) * SCIPgetTransObjscale(scip) + SCIPgetTransObjoffset(scip)) );
dualboundchg = TRUE;
}
/* check, whether conflicts were created */
nconflicts = 0;
if( sepadata->applyconflicts && !disabledualreductions && SCIPgetNConflictConssApplied(subscip) > 0 )
{
SCIP_HASHMAP* consmap;
int hashtablesize;
assert(SCIPgetNConflictConssApplied(subscip) < (SCIP_Longint) INT_MAX);
hashtablesize = (int) SCIPgetNConflictConssApplied(subscip);
assert(hashtablesize < INT_MAX/5);
hashtablesize *= 5;
/* create the variable mapping hash map */
SCIP_CALL( SCIPhashmapCreate(&consmap, SCIPblkmem(scip), SCIPcalcHashtableSize(hashtablesize)) );
/* loop over all constraint handlers that might contain conflict constraints */
for( i = 0; i < nconshdlrs; ++i)
{
/* copy constraints that have been created in FD run */
if( conshdlrs[i] != NULL && SCIPconshdlrGetNConss(conshdlrs[i]) > oldnconss[i] )
{
SCIP_CONS** conss;
int c;
int nconss;
nconss = SCIPconshdlrGetNConss(conshdlrs[i]);
conss = SCIPconshdlrGetConss(conshdlrs[i]);
/* loop over all constraints that have been added in sub-SCIP run, these are the conflicts */
for( c = oldnconss[i]; c < nconss; ++c)
{
SCIP_CONS* cons;
SCIP_CONS* conscopy;
cons = conss[c];
assert(cons != NULL);
success = FALSE;
SCIP_CALL( SCIPgetConsCopy(subscip, scip, cons, &conscopy, conshdlrs[i], varmapbw, consmap, NULL,
SCIPconsIsInitial(cons), SCIPconsIsSeparated(cons), SCIPconsIsEnforced(cons), SCIPconsIsChecked(cons),
SCIPconsIsPropagated(cons), TRUE, FALSE, SCIPconsIsDynamic(cons),
SCIPconsIsRemovable(cons), FALSE, TRUE, &success) );
if( success )
{
nconflicts++;
SCIP_CALL( SCIPaddCons(scip, conscopy) );
SCIP_CALL( SCIPreleaseCons(scip, &conscopy) );
}
else
{
SCIPdebugMessage("failed to copy conflict constraint %s back to original SCIP\n", SCIPconsGetName(cons));
}
}
}
}
SCIPhashmapFree(&consmap);
}
/* check, whether tighter global bounds were detected */
nbdchgs = 0;
if( sepadata->applybdchgs && !disabledualreductions )
for( i = 0; i < nvars; ++i )
{
SCIP_Bool infeasible;
SCIP_Bool tightened;
assert(SCIPisLE(scip, SCIPvarGetLbGlobal(vars[i]), SCIPvarGetLbGlobal(subvars[i])));
assert(SCIPisLE(scip, SCIPvarGetLbGlobal(subvars[i]), SCIPvarGetUbGlobal(subvars[i])));
assert(SCIPisLE(scip, SCIPvarGetUbGlobal(subvars[i]), SCIPvarGetUbGlobal(vars[i])));
/* update the bounds of the original SCIP, if a better bound was proven in the sub-SCIP */
SCIP_CALL( SCIPtightenVarUb(scip, vars[i], SCIPvarGetUbGlobal(subvars[i]), FALSE, &infeasible, &tightened) );
if( tightened )
nbdchgs++;
SCIP_CALL( SCIPtightenVarLb(scip, vars[i], SCIPvarGetLbGlobal(subvars[i]), FALSE, &infeasible, &tightened) );
if( tightened )
nbdchgs++;
}
n1startinfers = 0;
n2startinfers = 0;
/* install start values for inference branching */
if( sepadata->applyinfervals && (!sepadata->reducedinfer || soladded || nbdchgs+nconflicts > 0) )
{
for( i = 0; i < nvars; ++i )
{
SCIP_Real downinfer;
SCIP_Real upinfer;
SCIP_Real downvsids;
SCIP_Real upvsids;
SCIP_Real downconflen;
SCIP_Real upconflen;
/* copy downwards branching statistics */
downvsids = SCIPgetVarVSIDS(subscip, subvars[i], SCIP_BRANCHDIR_DOWNWARDS);
downconflen = SCIPgetVarAvgConflictlength(subscip, subvars[i], SCIP_BRANCHDIR_DOWNWARDS);
downinfer = SCIPgetVarAvgInferences(subscip, subvars[i], SCIP_BRANCHDIR_DOWNWARDS);
/* copy upwards branching statistics */
upvsids = SCIPgetVarVSIDS(subscip, subvars[i], SCIP_BRANCHDIR_UPWARDS);
upconflen = SCIPgetVarAvgConflictlength(subscip, subvars[i], SCIP_BRANCHDIR_UPWARDS);
upinfer = SCIPgetVarAvgInferences(subscip, subvars[i], SCIP_BRANCHDIR_UPWARDS);
/* memorize statistics */
if( downinfer+downconflen+downvsids > 0.0 || upinfer+upconflen+upvsids != 0 )
n1startinfers++;
if( downinfer+downconflen+downvsids > 0.0 && upinfer+upconflen+upvsids != 0 )
n2startinfers++;
SCIP_CALL( SCIPinitVarBranchStats(scip, vars[i], 0.0, 0.0, downvsids, upvsids, downconflen, upconflen, downinfer, upinfer, 0.0, 0.0) );
}
}
SCIPdebugPrintf("XXX Rapidlearning added %d conflicts, changed %d bounds, %s primal solution, %s dual bound improvement.\n", nconflicts, nbdchgs, soladded ? "found" : "no",
dualboundchg ? "found" : "no");
SCIPdebugPrintf("YYY Infervalues initialized on one side: %5.2f %% of variables, %5.2f %% on both sides\n",
100.0 * n1startinfers/(SCIP_Real)nvars, 100.0 * n2startinfers/(SCIP_Real)nvars);
/* change result pointer */
if( nconflicts > 0 || dualboundchg )
*result = SCIP_CONSADDED;
else if( nbdchgs > 0 )
*result = SCIP_REDUCEDDOM;
/* free local data */
SCIPfreeBufferArray(scip, &oldnconss);
SCIPfreeBufferArray(scip, &conshdlrs);
SCIPhashmapFree(&varmapbw);
TERMINATE:
/* free subproblem */
SCIPfreeBufferArray(scip, &subvars);
SCIP_CALL( SCIPfree(&subscip) );
return SCIP_OKAY;
}
