/** problem reading method of reader */
static
SCIP_DECL_READERREAD(readerReadFix)
{ /*lint --e{715}*/
assert(reader != NULL);
assert(strcmp(SCIPreaderGetName(reader), READER_NAME) == 0);
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
if( SCIPgetStage(scip) < SCIP_STAGE_PROBLEM )
{
SCIPerrorMessage("reading of fixing file is only possible after a problem was created\n");
return SCIP_READERROR;
}
/* free transformed problem, s.t. fixings are applied to the original problem */
SCIP_CALL( SCIPfreeTransform(scip) );
/* read (partial) solution from fixing file */
SCIP_CALL( readSol(scip, filename) );
*result = SCIP_SUCCESS;
return SCIP_OKAY;
}
/** transforms constraint data into data belonging to the transformed problem */
static
SCIP_DECL_CONSTRANS(consTransSamediff)
{ /*lint --e{715}*/
SCIP_CONSDATA* sourcedata;
SCIP_CONSDATA* targetdata;
assert(conshdlr != NULL);
assert(strcmp(SCIPconshdlrGetName(conshdlr), CONSHDLR_NAME) == 0);
assert(SCIPgetStage(scip) == SCIP_STAGE_TRANSFORMING);
assert(sourcecons != NULL);
assert(targetcons != NULL);
sourcedata = SCIPconsGetData(sourcecons);
assert(sourcedata != NULL);
/* create constraint data for target constraint */
SCIP_CALL( consdataCreate(scip, &targetdata,
sourcedata->itemid1, sourcedata->itemid2, sourcedata->type, sourcedata->node) );
/* create target constraint */
SCIP_CALL( SCIPcreateCons(scip, targetcons, SCIPconsGetName(sourcecons), conshdlr, targetdata,
SCIPconsIsInitial(sourcecons), SCIPconsIsSeparated(sourcecons), SCIPconsIsEnforced(sourcecons),
SCIPconsIsChecked(sourcecons), SCIPconsIsPropagated(sourcecons),
SCIPconsIsLocal(sourcecons), SCIPconsIsModifiable(sourcecons),
SCIPconsIsDynamic(sourcecons), SCIPconsIsRemovable(sourcecons), SCIPconsIsStickingAtNode(sourcecons)) );
return SCIP_OKAY;
}
/* reads problem from file */
SCIP_RETCODE SCIPreadDec(
SCIP* scip, /**< SCIP data structure */
const char* filename, /**< full path and name of file to read, or NULL if stdin should be used */
SCIP_RESULT* result /**< pointer to store the result of the file reading call */
)
{
SCIP_READER* reader;
DECINPUT decinput;
int i;
if( SCIPgetStage(scip) < SCIP_STAGE_TRANSFORMED )
SCIP_CALL( SCIPtransformProb(scip) );
reader = SCIPfindReader(scip, READER_NAME);
assert(reader != NULL);
/* initialize DEC input data */
decinput.file = NULL;
decinput.linebuf[0] = '\0';
SCIP_CALL( SCIPallocMemoryArray(scip, &decinput.token, DEC_MAX_LINELEN) ); /*lint !e506*/
decinput.token[0] = '\0';
SCIP_CALL( SCIPallocMemoryArray(scip, &decinput.tokenbuf, DEC_MAX_LINELEN) ); /*lint !e506*/
decinput.tokenbuf[0] = '\0';
for( i = 0; i < DEC_MAX_PUSHEDTOKENS; ++ i )
{
SCIP_CALL( SCIPallocMemoryArray(scip, &decinput.pushedtokens[i], DEC_MAX_LINELEN) ); /*lint !e506 !e866*/
}
decinput.npushedtokens = 0;
decinput.linenumber = 0;
decinput.linepos = 0;
decinput.section = DEC_START;
decinput.presolved = FALSE;
decinput.haspresolvesection = FALSE;
decinput.nblocks = NOVALUE;
decinput.blocknr = - 2;
decinput.haserror = FALSE;
/* read the file */
SCIP_CALL( readDECFile(scip, reader, &decinput, filename) );
/* free dynamically allocated memory */
SCIPfreeMemoryArray(scip, &decinput.token);
SCIPfreeMemoryArray(scip, &decinput.tokenbuf);
for( i = 0; i < DEC_MAX_PUSHEDTOKENS; ++ i )
{
SCIPfreeMemoryArray(scip, &decinput.pushedtokens[i]);
}
/* evaluate the result */
if( decinput.haserror )
return SCIP_READERROR;
else
{
*result = SCIP_SUCCESS;
}
return SCIP_OKAY;
}
/** informs solution debugger, that the given node will be freed */
SCIP_RETCODE SCIPdebugRemoveNode(
BMS_BLKMEM* blkmem, /**< block memory */
SCIP_SET* set, /**< global SCIP settings */
SCIP_NODE* node /**< node that will be freed */
)
{
assert(set != NULL);
assert(blkmem != NULL);
assert(node != NULL);
/* check if we are in the original problem and not in a sub MIP */
if( !isSolutionInMip(set) )
return SCIP_OKAY;
/* check if the incumbent solution is at least as good as the debug solution, so we can stop to check the debug solution */
if( debugSolIsAchieved(set) )
return SCIP_OKAY;
/* check if a solution will be cutoff in tree */
if( SCIPgetStage(set->scip) != SCIP_STAGE_FREESOLVE && SCIPgetStage(set->scip) != SCIP_STAGE_PRESOLVING && SCIPnodeGetType(node) != SCIP_NODETYPE_PROBINGNODE )
{
SCIP_Bool solisinnode;
solisinnode = FALSE;
SCIP_CALL( isSolutionInNode(blkmem, set, node, &solisinnode) );
/* wrong node will be cutoff */
if( solisinnode )
{
SCIPerrorMessage("debugging solution was cut off in local node %p at depth %d\n",
node, SCIPnodeGetDepth(node));
SCIPABORT();
}
}
/* remove node from the hash map */
if( solinnode != NULL )
{
SCIP_CALL( SCIPhashmapRemove(solinnode, (void*)node) );
}
return SCIP_OKAY;
}
/** problem reading method of reader */
static
SCIP_DECL_READERREAD(readerReadBlk)
{ /*lint --e{715} */
if( SCIPgetStage(scip) == SCIP_STAGE_INIT || SCIPgetNVars(scip) == 0 || SCIPgetNConss(scip) == 0 )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_DIALOG, NULL, "Please read in a problem before reading in the corresponding structure file!\n");
return SCIP_OKAY;
}
SCIP_CALL( SCIPreadBlk(scip, filename, result) );
return SCIP_OKAY;
}
/** reads a diff file */
static
SCIP_RETCODE readDiffFile(
SCIP* scip, /**< SCIP data structure */
LPINPUT* lpinput, /**< LP reading data */
const char* filename /**< name of the input file */
)
{
assert(lpinput != NULL);
/* open file */
lpinput->file = SCIPfopen(filename, "r");
if( lpinput->file == NULL )
{
SCIPerrorMessage("cannot open file <%s> for reading\n", filename);
SCIPprintSysError(filename);
return SCIP_NOFILE;
}
/* free transformed problem */
if( SCIPgetStage(scip) >= SCIP_STAGE_PROBLEM )
{
SCIP_CALL( SCIPfreeTransform(scip) );
}
/* parse the file */
lpinput->section = LP_START;
while( lpinput->section != LP_END && !hasError(lpinput) )
{
switch( lpinput->section )
{
case LP_START:
SCIP_CALL( readStart(scip, lpinput) );
break;
case LP_OBJECTIVE:
SCIP_CALL( readObjective(scip, lpinput) );
break;
case LP_END: /* this is already handled in the while() loop */
default:
SCIPerrorMessage("invalid Diff file section <%d>\n", lpinput->section);
return SCIP_INVALIDDATA;
}
}
/* close file */
SCIPfclose(lpinput->file);
return SCIP_OKAY;
}
/** dialog execution method for writing all known decompositions */
static
SCIP_DECL_DIALOGEXEC(GCGdialogExecWriteAllDecompositions)
{
SCIP_CALL( SCIPdialoghdlrAddHistory(dialoghdlr, dialog, NULL, FALSE) );
if( SCIPgetStage(scip) >= SCIP_STAGE_PROBLEM )
{
SCIP_CALL( writeAllDecompositions(scip, dialog, dialoghdlr, nextdialog) );
}
else
SCIPdialogMessage(scip, NULL, "no problem available\n");
*nextdialog = SCIPdialoghdlrGetRoot(dialoghdlr);
return SCIP_OKAY;
}
void ILPSolverSCIP::set_start_solution(const std::vector<double>& p_solution)
{
assert(p_solution.size() == d_cols.size());
// May not be able to set the solution after the problem has been solved or transformed.
if (SCIPgetStage(d_scip) == SCIP_STAGE_SOLVED)
reset_solution();
SCIP_SOL* sol;
SCIP_Bool ignored{ false };
call_scip(SCIPcreateSol, d_scip, &sol, nullptr);
// SCIP uses a double*, not a const double*, but ScaiILP demands a const std::vector<double>&.
// Internally, SCIP calls a single-variable setter for every variable with a by-value pass of the corresponding double,
// so the const_cast should not violate actual const-ness.
// Sadly, it is not avoidable since SCIP is not const-correct. (SCIP 6.0)
call_scip(SCIPsetSolVals, d_scip, sol, static_cast<int>(d_cols.size()), d_cols.data(), const_cast<double*>(p_solution.data()));
call_scip(SCIPaddSolFree, d_scip, &sol, &ignored);
}
SolutionStatus ILPSolverSCIP::get_status() const
{
int n = 0; // There are null-pointer accesses if called in the wrong stage, which happens if resetted.
switch (SCIPgetStage(d_scip))
{
case SCIP_STAGE_TRANSFORMED: [[fallthrough]];
case SCIP_STAGE_INITPRESOLVE: [[fallthrough]];
case SCIP_STAGE_PRESOLVING: [[fallthrough]];
case SCIP_STAGE_EXITPRESOLVE: [[fallthrough]];
case SCIP_STAGE_PRESOLVED: [[fallthrough]];
case SCIP_STAGE_INITSOLVE: [[fallthrough]];
case SCIP_STAGE_SOLVING: [[fallthrough]];
case SCIP_STAGE_SOLVED: [[fallthrough]];
case SCIP_STAGE_EXITSOLVE:
n = static_cast<int>(SCIPgetNSolsFound(d_scip));
}
SolutionStatus ret = (n > 0) ? SolutionStatus::SUBOPTIMAL : SolutionStatus::NO_SOLUTION;
// Handle all possible status values. Almost all will be reduced to SUBOPTIMAL or NO_SOLUTION.
switch (SCIPgetStatus(d_scip))
{
case SCIP_STATUS_OPTIMAL: return SolutionStatus::PROVEN_OPTIMAL;
case SCIP_STATUS_INFEASIBLE: return SolutionStatus::PROVEN_INFEASIBLE;
case SCIP_STATUS_UNBOUNDED: return SolutionStatus::PROVEN_UNBOUNDED;
case SCIP_STATUS_UNKNOWN: [[fallthrough]];
case SCIP_STATUS_INFORUNBD: [[fallthrough]];
case SCIP_STATUS_NODELIMIT: [[fallthrough]];
case SCIP_STATUS_TOTALNODELIMIT: [[fallthrough]];
case SCIP_STATUS_STALLNODELIMIT: [[fallthrough]];
case SCIP_STATUS_TIMELIMIT: [[fallthrough]];
case SCIP_STATUS_MEMLIMIT: [[fallthrough]];
case SCIP_STATUS_GAPLIMIT: [[fallthrough]];
case SCIP_STATUS_SOLLIMIT: [[fallthrough]];
case SCIP_STATUS_BESTSOLLIMIT: [[fallthrough]];
case SCIP_STATUS_RESTARTLIMIT: [[fallthrough]];
case SCIP_STATUS_USERINTERRUPT: [[fallthrough]];
case SCIP_STATUS_TERMINATE: [[fallthrough]];
default: return ret;
}
}
/** initializes the pricing problem for the given capacity */
static
SCIP_RETCODE initPricing(
SCIP* scip, /**< SCIP data structure */
SCIP_PRICERDATA* pricerdata, /**< pricer data */
SCIP* subscip, /**< pricing SCIP data structure */
SCIP_VAR** vars /**< variable array for the items */
)
{
SCIP_CONS** conss;
SCIP_Longint* vals;
SCIP_CONS* cons;
SCIP_VAR* var;
SCIP_Longint* weights;
SCIP_Longint capacity;
SCIP_Real dual;
int nitems;
int nvars;
int c;
assert( SCIPgetStage(subscip) == SCIP_STAGE_PROBLEM );
assert(pricerdata != NULL);
nitems = pricerdata->nitems;
conss = pricerdata->conss;
weights = pricerdata->weights;
capacity = pricerdata->capacity;
nvars = 0;
SCIP_CALL( SCIPallocBufferArray(subscip, &vals, nitems) );
/* create for each order, which is not assigned yet, a variable with objective coefficient */
for( c = 0; c < nitems; ++c )
{
cons = conss[c];
/* check if each constraint is setppc constraint */
assert( !strncmp( SCIPconshdlrGetName( SCIPconsGetHdlr(cons) ), "setppc", 6) );
/* constraints which are (locally) disabled/redundant are not of
* interest since the corresponding job is assigned to a packing
*/
if( !SCIPconsIsEnabled(cons) )
continue;
if( SCIPgetNFixedonesSetppc(scip, cons) == 1 )
{
/* disable constraint locally */
SCIP_CALL( SCIPdelConsLocal(scip, cons) );
continue;
}
/* dual value in original SCIP */
dual = SCIPgetDualsolSetppc(scip, cons);
SCIP_CALL( SCIPcreateVarBasic(subscip, &var, SCIPconsGetName(cons), 0.0, 1.0, dual, SCIP_VARTYPE_BINARY) );
SCIP_CALL( SCIPaddVar(subscip, var) );
vals[nvars] = weights[c];
vars[nvars] = var;
nvars++;
/* release variable */
SCIP_CALL( SCIPreleaseVar(subscip, &var) );
}
/* create capacity constraint */
SCIP_CALL( SCIPcreateConsBasicKnapsack(subscip, &cons, "capacity", nvars, vars, vals,
capacity) );
SCIP_CALL( SCIPaddCons(subscip, cons) );
SCIP_CALL( SCIPreleaseCons(subscip, &cons) );
/* add constraint of the branching decisions */
SCIP_CALL( addBranchingDecisionConss(scip, subscip, vars, pricerdata->conshdlr) );
/* avoid to generate columns which are fixed to zero */
SCIP_CALL( addFixedVarsConss(scip, subscip, vars, conss, nitems) );
SCIPfreeBufferArray(subscip, &vals);
return SCIP_OKAY;
}
/** perform dual presolving */
static
SCIP_RETCODE performDualfix(
SCIP* scip, /**< SCIP data structure */
int* nfixedvars, /**< pointer to store number of fixed variables */
SCIP_Bool* unbounded, /**< pointer to store if an unboundness was detected */
SCIP_Bool* cutoff /**< pointer to store if a cutoff was detected */
)
{
SCIP_VAR** vars;
int nvars;
int v;
/* get active problem variables */
vars = SCIPgetVars(scip);
nvars = SCIPgetNVars(scip);
/* look for fixable variables
* loop backwards, since a variable fixing can change the current and the subsequent slots in the vars array
*/
for( v = nvars - 1; v >= 0; --v )
{
SCIP_VAR* var;
SCIP_Real bound;
SCIP_Real obj;
SCIP_Bool infeasible;
SCIP_Bool fixed;
var = vars[v];
assert(var != NULL);
/* don't perform dual presolving operations on deleted variables */
if( SCIPvarIsDeleted(var) )
continue;
/* ignore already fixed variables (use feasibility tolerance since this is used in SCIPfixVar() */
if( SCIPisFeasEQ(scip, SCIPvarGetLbLocal(var), SCIPvarGetUbLocal(var)) )
continue;
obj = SCIPvarGetObj(var);
/* if the objective coefficient of the variable is 0 and it may be rounded both
* up and down, then fix it to the closest feasible value to 0 */
if( SCIPisZero(scip, obj) && SCIPvarMayRoundDown(var) && SCIPvarMayRoundUp(var) )
{
SCIP_Real roundbound;
bound = SCIPvarGetLbGlobal(var);
if( SCIPisLT(scip, bound, 0.0) )
{
if( SCIPisLE(scip, 0.0, SCIPvarGetUbGlobal(var)) )
bound = 0.0;
else
{
/* try to take an integer value, only for polishing */
roundbound = SCIPfloor(scip, SCIPvarGetUbGlobal(var));
if( roundbound < bound )
bound = SCIPvarGetUbGlobal(var);
else
bound = roundbound;
}
}
else
{
/* try to take an integer value, only for polishing */
roundbound = SCIPceil(scip, bound);
if( roundbound < SCIPvarGetUbGlobal(var) )
bound = roundbound;
}
SCIPdebugMessage("fixing variable <%s> with objective 0 to %g\n", SCIPvarGetName(var), bound);
}
else
{
/* if it is always possible to round variable in direction of objective value, fix it to its proper bound */
if( SCIPvarMayRoundDown(var) && !SCIPisNegative(scip, obj) )
{
bound = SCIPvarGetLbGlobal(var);
if ( SCIPisInfinity(scip, -bound) )
{
/* variable can be fixed to -infinity */
if ( SCIPgetStage(scip) > SCIP_STAGE_PRESOLVING )
{
/* Fixing variables to infinity is not allowed after presolving, since LP-solvers cannot handle this
* consistently. We thus have to ignore this (should better be handled in presolving). */
continue;
}
if ( SCIPisZero(scip, obj) && SCIPvarGetNLocksUp(var) == 1 )
{
/* Variable is only contained in one constraint: we hope that the corresponding constraint handler is
* clever enough to set/aggregate the variable to something more useful than -infinity and do nothing
* here. */
continue;
}
}
SCIPdebugMessage("fixing variable <%s> with objective %g and %d uplocks to lower bound %g\n",
SCIPvarGetName(var), SCIPvarGetObj(var), SCIPvarGetNLocksUp(var), bound);
}
else if( SCIPvarMayRoundUp(var) && !SCIPisPositive(scip, obj) )
{
bound = SCIPvarGetUbGlobal(var);
if ( SCIPisInfinity(scip, bound) )
{
/* variable can be fixed to infinity */
if ( SCIPgetStage(scip) > SCIP_STAGE_PRESOLVING )
{
/* Fixing variables to infinity is not allowed after presolving, since LP-solvers cannot handle this
* consistently. We thus have to ignore this (should better be handled in presolving). */
continue;
}
if ( SCIPisZero(scip, obj) && SCIPvarGetNLocksDown(var) == 1 )
{
/* Variable is only contained in one constraint: we hope that the corresponding constraint handler is
* clever enough to set/aggregate the variable to something more useful than +infinity and do nothing
* here */
continue;
}
}
SCIPdebugMessage("fixing variable <%s> with objective %g and %d downlocks to upper bound %g\n",
SCIPvarGetName(var), SCIPvarGetObj(var), SCIPvarGetNLocksDown(var), bound);
}
else
continue;
}
if( SCIPisInfinity(scip, REALABS(bound)) && !SCIPisZero(scip, obj) )
{
SCIPdebugMessage(" -> unbounded fixing\n");
SCIPverbMessage(scip, SCIP_VERBLEVEL_NORMAL, NULL,
"problem infeasible or unbounded: variable <%s> with objective %.15g can be made infinitely %s\n",
SCIPvarGetName(var), SCIPvarGetObj(var), bound < 0.0 ? "small" : "large");
*unbounded = TRUE;
return SCIP_OKAY;
}
/* apply the fixing */
SCIPdebugMessage("apply fixing of variable %s to %g\n", SCIPvarGetName(var), bound);
SCIP_CALL( SCIPfixVar(scip, var, bound, &infeasible, &fixed) );
if( infeasible )
{
SCIPdebugMessage(" -> infeasible fixing\n");
*cutoff = TRUE;
return SCIP_OKAY;
}
assert(fixed || (SCIPgetStage(scip) == SCIP_STAGE_SOLVING && SCIPisFeasEQ(scip, bound, SCIPvarGetLbLocal(var))
&& SCIPisFeasEQ(scip, bound, SCIPvarGetUbLocal(var))));
(*nfixedvars)++;
}
return SCIP_OKAY;
}
/** reduced cost propagation method for an LP solution */
static
SCIP_DECL_PROPEXEC(propExecRedcost)
{ /*lint --e{715}*/
SCIP_PROPDATA* propdata;
SCIP_COL** cols;
SCIP_Real requiredredcost;
SCIP_Real cutoffbound;
SCIP_Real lpobjval;
SCIP_Bool propbinvars;
SCIP_Bool cutoff;
int nchgbds;
int ncols;
int c;
*result = SCIP_DIDNOTRUN;
/* in case we have a zero objective function, we skip the reduced cost propagator */
if( SCIPgetNObjVars(scip) == 0 )
return SCIP_OKAY;
/* propagator can only be applied during solving stage */
if( SCIPgetStage(scip) < SCIP_STAGE_SOLVING )
return SCIP_OKAY;
/* we cannot apply reduced cost fixing, if we want to solve exactly */
/**@todo implement reduced cost fixing with interval arithmetics */
if( SCIPisExactSolve(scip) )
return SCIP_OKAY;
/* only call propagator, if the current node has an LP */
if( !SCIPhasCurrentNodeLP(scip) )
return SCIP_OKAY;
/* only call propagator, if an optimal LP solution is at hand */
if( SCIPgetLPSolstat(scip) != SCIP_LPSOLSTAT_OPTIMAL )
return SCIP_OKAY;
/* only call propagator, if the current LP is a valid relaxation */
if( !SCIPisLPRelax(scip) )
return SCIP_OKAY;
/* we cannot apply reduced cost strengthening, if no simplex basis is available */
if( !SCIPisLPSolBasic(scip) )
return SCIP_OKAY;
/* get current cutoff bound */
cutoffbound = SCIPgetCutoffbound(scip);
/* reduced cost strengthening can only be applied, if we have a finite cutoff */
if( SCIPisInfinity(scip, cutoffbound) )
return SCIP_OKAY;
/* get LP columns */
cols = SCIPgetLPCols(scip);
ncols = SCIPgetNLPCols(scip);
/* do nothing if the LP has no columns (is empty) */
if( ncols == 0 )
return SCIP_OKAY;
/* get propagator data */
propdata = SCIPpropGetData(prop);
assert(propdata != NULL);
/* chack if all integral variables are fixed and the continuous variables should not be propagated */
if( !propdata->continuous && SCIPgetNPseudoBranchCands(scip) == 0 )
return SCIP_OKAY;
/* get LP objective value */
lpobjval = SCIPgetLPObjval(scip);
/* check if binary variables should be propagated */
propbinvars = (SCIPgetDepth(scip) == 0) || (cutoffbound - lpobjval < 5 * propdata->maxredcost);
/* skip the propagator if the problem has only binary variables and those should not be propagated */
if( !propbinvars && SCIPgetNVars(scip) == SCIPgetNBinVars(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
cutoff = FALSE;
nchgbds = 0;
/* compute the required reduced cost which are needed for a binary variable to be fixed */
requiredredcost = cutoffbound - lpobjval;
SCIPdebugMessage("lpobjval <%g>, cutoffbound <%g>, max reduced <%g>, propgate binary %u, use implics %u\n",
lpobjval, cutoffbound, propdata->maxredcost, propbinvars, propdata->usefullimplics);
/* check reduced costs for non-basic columns */
for( c = 0; c < ncols && !cutoff; ++c )
{
SCIP_VAR* var;
var = SCIPcolGetVar(cols[c]);
/* skip continuous variables in case the corresponding parameter is set */
if( !propdata->continuous && !SCIPvarIsIntegral(var) )
continue;
if( SCIPvarIsBinary(var) )
{
if( propbinvars )
{
if( SCIPgetDepth(scip) == 0 )
{
SCIP_CALL( propagateRootRedcostBinvar(scip, propdata, var, cols[c], cutoffbound, &nchgbds) );
}
else
{
SCIP_CALL( propagateRedcostBinvar(scip, propdata, var, cols[c], requiredredcost, &nchgbds, &cutoff) );
}
}
}
else
{
SCIP_CALL( propagateRedcostVar(scip, var, cols[c], lpobjval, cutoffbound, &nchgbds) );
}
}
if( cutoff )
{
*result = SCIP_CUTOFF;
SCIPdebugMessage("node %"SCIP_LONGINT_FORMAT": detected cutoff\n",
SCIPnodeGetNumber(SCIPgetCurrentNode(scip)));
}
else if( nchgbds > 0 )
{
*result = SCIP_REDUCEDDOM;
SCIPdebugMessage("node %"SCIP_LONGINT_FORMAT": %d bound changes (max redcost <%g>)\n",
SCIPnodeGetNumber(SCIPgetCurrentNode(scip)) , nchgbds, propdata->maxredcost);
}
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;
}
/** execution method of presolver */
static
SCIP_DECL_PRESOLEXEC(presolExecDualagg)
{ /*lint --e{715}*/
SCIPMILPMATRIX* matrix;
SCIP_Bool initialized;
SCIP_Bool complete;
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
if( (SCIPgetStage(scip) != SCIP_STAGE_PRESOLVING) || SCIPinProbing(scip) || SCIPisNLPEnabled(scip) )
return SCIP_OKAY;
if( SCIPisStopped(scip) || SCIPgetNActivePricers(scip) > 0 )
return SCIP_OKAY;
if( SCIPgetNBinVars(scip) == 0 )
return SCIP_OKAY;
if( !SCIPallowDualReds(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
matrix = NULL;
SCIP_CALL( SCIPmatrixCreate(scip, &matrix, &initialized, &complete) );
/* we only work on pure MIPs currently */
if( initialized && complete )
{
AGGRTYPE* aggtypes;
SCIP_VAR** binvars;
int nvaragg;
int ncols;
ncols = SCIPmatrixGetNColumns(matrix);
nvaragg = 0;
SCIP_CALL( SCIPallocBufferArray(scip, &aggtypes, ncols) );
BMSclearMemoryArray(aggtypes, ncols);
SCIP_CALL( SCIPallocBufferArray(scip, &binvars, ncols) );
SCIPdebug( BMSclearMemoryArray(binvars, ncols) );
/* search for aggregations */
SCIP_CALL( findUplockAggregations(scip, matrix, &nvaragg, aggtypes, binvars) );
SCIP_CALL( findDownlockAggregations(scip, matrix, &nvaragg, aggtypes, binvars) );
/* apply aggregations, if we found any */
if( nvaragg > 0 )
{
int v;
for( v = 0; v < ncols; v++ )
{
if( aggtypes[v] != NOAGG )
{
SCIP_Bool infeasible;
SCIP_Bool redundant;
SCIP_Bool aggregated;
SCIP_Real ub;
SCIP_Real lb;
ub = SCIPmatrixGetColUb(matrix, v);
lb = SCIPmatrixGetColLb(matrix, v);
/* aggregate variable */
assert(binvars[v] != NULL);
if( aggtypes[v] == BIN0UBOUND )
{
SCIP_CALL( SCIPaggregateVars(scip, SCIPmatrixGetVar(matrix, v), binvars[v], 1.0, ub-lb,
ub, &infeasible, &redundant, &aggregated) );
}
else
{
assert(aggtypes[v] == BIN0LBOUND);
SCIP_CALL( SCIPaggregateVars(scip, SCIPmatrixGetVar(matrix, v), binvars[v], 1.0, lb-ub,
lb, &infeasible, &redundant, &aggregated) );
}
/* infeasible aggregation */
if( infeasible )
{
SCIPdebugMessage(" -> infeasible aggregation\n");
*result = SCIP_CUTOFF;
return SCIP_OKAY;
}
if( aggregated )
(*naggrvars)++;
}
}
/* set result pointer */
if( (*naggrvars) > 0 )
*result = SCIP_SUCCESS;
}
SCIPfreeBufferArray(scip, &binvars);
SCIPfreeBufferArray(scip, &aggtypes);
}
SCIPmatrixFree(scip, &matrix);
return SCIP_OKAY;
}
/** execution method of primal heuristic */
static
SCIP_DECL_HEUREXEC(heurExecGcgrens)
{ /*lint --e{715}*/
SCIP* masterprob;
SCIP_HEURDATA* heurdata; /* heuristic's data */
SCIP_Longint nstallnodes; /* number of stalling nodes for the subproblem */
assert( heur != NULL );
assert( scip != NULL );
assert( result != NULL );
/* get master problem */
masterprob = GCGrelaxGetMasterprob(scip);
assert( masterprob != NULL);
/* get heuristic's data */
heurdata = SCIPheurGetData(heur);
assert( heurdata != NULL );
*result = SCIP_DELAYED;
/* do not execute the heuristic on invalid relaxation solutions
* (which is the case if the node has been cut off)
*/
if( !SCIPisRelaxSolValid(scip) )
{
SCIPdebugMessage("skipping GCG RENS: invalid relaxation solution\n");
return SCIP_OKAY;
}
/* only call heuristic, if an optimal LP solution is at hand */
if( SCIPgetStage(masterprob) > SCIP_STAGE_SOLVING || SCIPgetLPSolstat(masterprob) != SCIP_LPSOLSTAT_OPTIMAL )
return SCIP_OKAY;
*result = SCIP_DIDNOTRUN;
/* only continue with some fractional variables */
if( SCIPgetNExternBranchCands(scip) == 0 )
return SCIP_OKAY;
/* calculate the maximal number of branching nodes until heuristic is aborted */
nstallnodes = (SCIP_Longint)(heurdata->nodesquot * SCIPgetNNodes(scip));
/* reward RENS if it succeeded often */
nstallnodes = (SCIP_Longint)(nstallnodes * 3.0 * (SCIPheurGetNBestSolsFound(heur)+1.0)/(SCIPheurGetNCalls(heur) + 1.0));
nstallnodes -= 100 * SCIPheurGetNCalls(heur); /* count the setup costs for the sub-SCIP as 100 nodes */
nstallnodes += heurdata->nodesofs;
/* determine the node limit for the current process */
nstallnodes -= heurdata->usednodes;
nstallnodes = MIN(nstallnodes, heurdata->maxnodes);
/* check whether we have enough nodes left to call subproblem solving */
if( nstallnodes < heurdata->minnodes )
{
SCIPdebugMessage("skipping RENS: nstallnodes=%"SCIP_LONGINT_FORMAT", minnodes=%"SCIP_LONGINT_FORMAT"\n", nstallnodes, heurdata->minnodes);
return SCIP_OKAY;
}
if( SCIPisStopped(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
SCIP_CALL( SCIPapplyGcgrens(scip, heur, result, heurdata->minfixingrate, heurdata->minimprove,
heurdata->maxnodes, nstallnodes, heurdata->binarybounds, heurdata->uselprows) );
return SCIP_OKAY;
}
/** ensure that maxindex + 1 rows can be represented in data arrays; memory gets reallocated with 10% extra space
* to save some time for future allocations */
static
SCIP_RETCODE heurdataEnsureArraySize(
SCIP* scip, /**< SCIP data structure */
SCIP_HEURDATA* heurdata, /**< heuristic data */
int maxindex /**< row index at hand (size must be at least this large) */
)
{
int newsize;
int r;
/* maxindex fits in current array -> nothing to do */
if( maxindex < heurdata->memsize )
return SCIP_OKAY;
/* new memory size is the max index + 1 plus 10% additional space */
newsize = (int)SCIPfeasCeil(scip, (maxindex + 1) * 1.1);
assert(newsize > heurdata->memsize);
assert(heurdata->memsize >= 0);
/* alloc memory arrays for row information */
if( heurdata->memsize == 0 )
{
SCIP_VAR** vars;
int v;
int nvars;
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->rowinfinitiesdown, newsize) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->rowinfinitiesup, newsize) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->rowmeans, newsize) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->rowvariances, newsize) );
assert(SCIPgetStage(scip) == SCIP_STAGE_SOLVING);
vars = SCIPgetVars(scip);
nvars = SCIPgetNVars(scip);
assert(nvars > 0);
/* allocate variable update event processing array storage */
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->varfilterposs, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->varposs, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->updatedvars, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->currentubs, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &heurdata->currentlbs, nvars) );
heurdata->varpossmemsize = nvars;
heurdata->nupdatedvars = 0;
/* init variable event processing data */
for( v = 0; v < nvars; ++v )
{
assert(SCIPvarIsActive(vars[v]));
assert(SCIPvarGetProbindex(vars[v]) == v);
/* set up variable events to catch bound changes */
SCIP_CALL( SCIPcatchVarEvent(scip, vars[v], EVENT_DISTRIBUTION, heurdata->eventhdlr, NULL, &(heurdata->varfilterposs[v])) );
assert(heurdata->varfilterposs[v] >= 0);
heurdata->varposs[v] = -1;
heurdata->updatedvars[v] = NULL;
heurdata->currentlbs[v] = SCIP_INVALID;
heurdata->currentubs[v] = SCIP_INVALID;
}
}
else
{
SCIP_CALL( SCIPreallocBufferArray(scip, &heurdata->rowinfinitiesdown, newsize) );
SCIP_CALL( SCIPreallocBufferArray(scip, &heurdata->rowinfinitiesup, newsize) );
SCIP_CALL( SCIPreallocBufferArray(scip, &heurdata->rowmeans, newsize) );
SCIP_CALL( SCIPreallocBufferArray(scip, &heurdata->rowvariances, newsize) );
}
/* loop over extended arrays and invalidate data to trigger initialization of this row when necessary */
for( r = heurdata->memsize; r < newsize; ++r )
{
heurdata->rowmeans[r] = SCIP_INVALID;
heurdata->rowvariances[r] = SCIP_INVALID;
heurdata->rowinfinitiesdown[r] = 0;
heurdata->rowinfinitiesup[r] = 0;
}
/* adjust memsize */
heurdata->memsize = newsize;
return SCIP_OKAY;
}
SCIP_RETCODE SCIPconshdlrBenders::sepaBenders(
SCIP * scip,
SCIP_CONSHDLR * conshdlr,
SCIP_SOL * sol,
whereFrom where,
SCIP_RESULT * result)
{
OsiCuts cs; /**< Benders cut placeholder */
SCIP_Real * vals = NULL; /**< current solution */
#if 1
if (scip_checkpriority_ < 0)
{
/** consider incumbent solutions only */
double primObj = SCIPgetPrimalbound(scip);
double currObj = SCIPgetSolOrigObj(scip, sol);
if (SCIPisLT(scip, primObj, currObj))
{
DSPdebugMessage(" -> primObj %e currObj %e\n", primObj, currObj);
return SCIP_OKAY;
}
}
#endif
/** allocate memory */
SCIP_CALL(SCIPallocMemoryArray(scip, &vals, nvars_));
/** get current solution */
SCIP_CALL(SCIPgetSolVals(scip, sol, nvars_, vars_, vals));
/** TODO The following filter does not work, meaning that it provides suboptimal solution.
* I do not know the reason. */
#if 0
double maxviol = 1.e-10;
for (int j = 0; j < nvars_ - naux_; ++j)
{
SCIP_VARTYPE vartype = SCIPvarGetType(vars_[j]);
if (vartype == SCIP_VARTYPE_CONTINUOUS) continue;
double viol = 0.5 - fabs(vals[j] - floor(vals[j]) - 0.5);
if (viol > maxviol)
maxviol = viol;
}
DSPdebugMessage("maximum violation %e\n", maxviol);
if (where != from_scip_check &&
where != from_scip_enfolp &&
where != from_scip_enfops &&
maxviol > 1.e-7)
{
printf("where %d maxviol %e\n", where, maxviol);
/** free memory */
SCIPfreeMemoryArray(scip, &vals);
return SCIP_OKAY;
}
#endif
#ifdef DSP_DEBUG2
double minvals = COIN_DBL_MAX;
double maxvals = -COIN_DBL_MAX;
double sumvals = 0.;
double ssvals = 0.;
//printf("nvars_ %d naux_ %d nAuxvars_ %d\n", nvars_, naux_, tss_->nAuxvars_);
for (int j = 0; j < nvars_ - naux_; ++j)
{
// if (vals[j] < 0 || vals[j] > 1)
// printf("solution %d has value %e.\n", j, vals[j]);
sumvals += vals[j];
ssvals += vals[j] * vals[j];
minvals = minvals > vals[j] ? vals[j] : minvals;
maxvals = maxvals < vals[j] ? vals[j] : maxvals;
}
DSPdebugMessage("solution: min %e max %e avg %e sum %e two-norm %e\n",
minvals, maxvals, sumvals / nvars_, sumvals, sqrt(ssvals));
#endif
#define SCAN_GLOBAL_CUT_POOL
#ifdef SCAN_GLOBAL_CUT_POOL
if (SCIPgetStage(scip) == SCIP_STAGE_SOLVING ||
SCIPgetStage(scip) == SCIP_STAGE_SOLVED ||
SCIPgetStage(scip) == SCIP_STAGE_EXITSOLVE)
{
bool addedPoolCut = false;
int numPoolCuts = SCIPgetNPoolCuts(scip);
int numCutsToScan = 100;
SCIP_CUT ** poolcuts = SCIPgetPoolCuts(scip);
for (int i = numPoolCuts - 1; i >= 0; --i)
{
if (i < 0) break;
if (numCutsToScan == 0) break;
/** retrieve row */
SCIP_ROW * poolcutrow = SCIPcutGetRow(poolcuts[i]);
/** benders? */
if (strcmp(SCIProwGetName(poolcutrow), "benders") != 0)
continue;
/** counter */
numCutsToScan--;
if (SCIPgetCutEfficacy(scip, sol, poolcutrow) > 1.e-6)
{
if (where == from_scip_sepalp ||
where == from_scip_sepasol ||
where == from_scip_enfolp)
{
/** add cut */
SCIP_Bool infeasible;
SCIP_CALL(SCIPaddCut(scip, sol, poolcutrow,
FALSE, /**< force cut */
&infeasible));
if (infeasible)
*result = SCIP_CUTOFF;
else //if (*result != SCIP_CUTOFF)
*result = SCIP_SEPARATED;
}
else
*result = SCIP_INFEASIBLE;
addedPoolCut = true;
break;
}
}
if (addedPoolCut)
{
DSPdebugMessage("Added pool cut\n");
/** free memory */
SCIPfreeMemoryArray(scip, &vals);
return SCIP_OKAY;
}
}
#endif
/** generate Benders cuts */
assert(tss_);
tss_->generateCuts(nvars_, vals, &cs);
/** If found Benders cuts */
for (int i = 0; i < cs.sizeCuts(); ++i)
{
/** get cut pointer */
OsiRowCut * rc = cs.rowCutPtr(i);
if (!rc) continue;
const CoinPackedVector cutrow = rc->row();
if (cutrow.getNumElements() == 0) continue;
/** is optimality cut? */
bool isOptimalityCut = false;
for (int j = nvars_ - naux_; j < nvars_; ++j)
{
if (cutrow.getMaxIndex() == j)
{
isOptimalityCut = true;
break;
}
}
double efficacy = rc->violated(vals) / cutrow.twoNorm();
SCIP_Bool isEfficacious = efficacy > 1.e-6;
#define KK_TEST
#ifdef KK_TEST
if (SCIPgetStage(scip) == SCIP_STAGE_INITSOLVE ||
SCIPgetStage(scip) == SCIP_STAGE_SOLVING)
{
/** create empty row */
SCIP_ROW * row = NULL;
SCIP_CALL(SCIPcreateEmptyRowCons(scip, &row, conshdlr, "benders", rc->lb(), SCIPinfinity(scip),
FALSE, /**< is row local? */
FALSE, /**< is row modifiable? */
FALSE /**< is row removable? can this be TRUE? */));
/** cache the row extension and only flush them if the cut gets added */
SCIP_CALL(SCIPcacheRowExtensions(scip, row));
/** collect all non-zero coefficients */
for (int j = 0; j < cutrow.getNumElements(); ++j)
SCIP_CALL(SCIPaddVarToRow(scip, row, vars_[cutrow.getIndices()[j]], cutrow.getElements()[j]));
DSPdebugMessage("found Benders (%s) cut: act=%f, lhs=%f, norm=%f, eff=%f, min=%f, max=%f (range=%f)\n",
isOptimalityCut ? "opti" : "feas",
SCIPgetRowLPActivity(scip, row), SCIProwGetLhs(row), SCIProwGetNorm(row),
SCIPgetCutEfficacy(scip, sol, row),
SCIPgetRowMinCoef(scip, row), SCIPgetRowMaxCoef(scip, row),
SCIPgetRowMaxCoef(scip, row)/SCIPgetRowMinCoef(scip, row));
/** flush all changes before adding cut */
SCIP_CALL(SCIPflushRowExtensions(scip, row));
DSPdebugMessage("efficacy %e isEfficatious %d\n", efficacy, isEfficacious);
if (isEfficacious)
{
if (where == from_scip_sepalp ||
where == from_scip_sepasol ||
where == from_scip_enfolp)
{
/** add cut */
SCIP_Bool infeasible;
SCIP_CALL(SCIPaddCut(scip, sol, row,
FALSE, /**< force cut */
&infeasible));
if (infeasible)
*result = SCIP_CUTOFF;
else //if (*result != SCIP_CUTOFF)
*result = SCIP_SEPARATED;
}
else
*result = SCIP_INFEASIBLE;
}
/** add cut to global pool */
SCIP_CALL(SCIPaddPoolCut(scip, row));
DSPdebugMessage("number of cuts in global cut pool: %d\n", SCIPgetNPoolCuts(scip));
/** release the row */
SCIP_CALL(SCIPreleaseRow(scip, &row));
}
else if (isEfficacious &&
where != from_scip_sepalp &&
where != from_scip_sepasol &&
where != from_scip_enfolp)
*result = SCIP_INFEASIBLE;
#else
if (where == from_scip_sepalp ||
where == from_scip_sepasol ||
where == from_scip_enfolp)
{
/** create empty row */
SCIP_ROW * row = NULL;
SCIP_CALL(SCIPcreateEmptyRowCons(scip, &row, conshdlr, "benders", rc->lb(), SCIPinfinity(scip),
FALSE, /**< is row local? */
FALSE, /**< is row modifiable? */
FALSE /**< is row removable? can this be TRUE? */));
/** cache the row extension and only flush them if the cut gets added */
SCIP_CALL(SCIPcacheRowExtensions(scip, row));
/** collect all non-zero coefficients */
for (int j = 0; j < cutrow.getNumElements(); ++j)
SCIP_CALL(SCIPaddVarToRow(scip, row, vars_[cutrow.getIndices()[j]], cutrow.getElements()[j]));
DSPdebugMessage("found Benders (%s) cut: act=%f, lhs=%f, norm=%f, eff=%f, min=%f, max=%f (range=%f)\n",
isOptimalityCut ? "opti" : "feas",
SCIPgetRowLPActivity(scip, row), SCIProwGetLhs(row), SCIProwGetNorm(row),
SCIPgetCutEfficacy(scip, NULL, row),
SCIPgetRowMinCoef(scip, row), SCIPgetRowMaxCoef(scip, row),
SCIPgetRowMaxCoef(scip, row)/SCIPgetRowMinCoef(scip, row));
/** flush all changes before adding cut */
SCIP_CALL(SCIPflushRowExtensions(scip, row));
/** is cut efficacious? */
if (isOptimalityCut)
{
efficacy = SCIPgetCutEfficacy(scip, sol, row);
isEfficacious = SCIPisCutEfficacious(scip, sol, row);
}
else
{
efficacy = rc->violated(vals);
isEfficacious = efficacy > 1.e-6;
}
if (isEfficacious)
{
/** add cut */
SCIP_Bool infeasible;
SCIP_CALL(SCIPaddCut(scip, sol, row,
FALSE, /**< force cut */
&infeasible));
if (infeasible)
*result = SCIP_CUTOFF;
else if (*result != SCIP_CUTOFF)
*result = SCIP_SEPARATED;
}
/** add cut to global pool */
SCIP_CALL(SCIPaddPoolCut(scip, row));
/** release the row */
SCIP_CALL(SCIPreleaseRow(scip, &row));
}
else
{
if (isOptimalityCut)
{
efficacy = rc->violated(vals) / cutrow.twoNorm();
isEfficacious = efficacy > 0.05;
}
else
{
efficacy = rc->violated(vals);
isEfficacious = efficacy > 1.e-6;
}
DSPdebugMessage("%s efficacy %e\n", isOptimalityCut ? "Opti" : "Feas", efficacy);
if (isEfficacious == TRUE)
*result = SCIP_INFEASIBLE;
}
#endif
}
/** free memory */
SCIPfreeMemoryArray(scip, &vals);
return SCIP_OKAY;
}
/** propagator to force finding the debugging solution */
static
SCIP_DECL_PROPEXEC(propExecDebug)
{ /*lint --e{715}*/
SCIP_VAR** vars;
int nvars;
int i;
assert(scip != NULL);
assert(result != NULL);
*result = SCIP_DIDNOTFIND;
/* check if we are in the original problem and not in a sub MIP */
if( !isSolutionInMip(scip->set) )
return SCIP_OKAY;
if( SCIPgetStage(scip) != SCIP_STAGE_SOLVING )
return SCIP_OKAY;
/* check if the incumbent solution is at least as good as the debug solution, so we can stop to check the debug solution */
if( debugSolIsAchieved(scip->set) )
return SCIP_OKAY;
#if 1
/* solve at least one LP */
if( SCIPgetNLPIterations(scip) == 0 )
return SCIP_OKAY;
#endif
vars = SCIPgetOrigVars(scip);
nvars = SCIPgetNOrigVars(scip);
for( i = 0; i < nvars; ++i )
{
SCIP_Real solval;
SCIP_Real lb;
SCIP_Real ub;
SCIP_Bool infeasible;
SCIP_Bool fixed;
SCIP_CALL( getSolutionValue(scip->set, vars[i], &solval) );
if( solval == SCIP_UNKNOWN ) /*lint !e777*/
{
SCIPerrorMessage("original variable without debugging solution value\n");
SCIPABORT();
}
lb = SCIPvarGetLbGlobal(vars[i]);
ub = SCIPvarGetUbGlobal(vars[i]);
if( SCIPisLT(scip, solval, lb) || SCIPisGT(scip, solval, ub) )
{
SCIPerrorMessage("solution value %.15g of <%s> outside bounds loc=[%.15g,%.15g], glb=[%.15g,%.15g]\n",
solval, SCIPvarGetName(vars[i]), lb, ub, SCIPvarGetLbGlobal(vars[i]), SCIPvarGetUbGlobal(vars[i]));
SCIPABORT();
}
SCIP_CALL( SCIPfixVar(scip, vars[i], solval, &infeasible, &fixed) );
if( infeasible )
*result = SCIP_CUTOFF;
else if( fixed )
*result = SCIP_REDUCEDDOM;
}
return SCIP_OKAY;
}
/** problem reading method of reader
*
* In order to determine the type of the file, we have to open it. Thus, it has to be opened
* twice. This might be removed, but is likely to not hurt the performance too much.
*/
static
SCIP_DECL_READERREAD(readerReadSol)
{ /*lint --e{715}*/
SCIP_FILE* file;
char buffer[SCIP_MAXSTRLEN];
char *s;
assert(reader != NULL);
assert(strcmp(SCIPreaderGetName(reader), READER_NAME) == 0);
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
if( SCIPgetStage(scip) < SCIP_STAGE_PROBLEM )
{
SCIPerrorMessage("reading of solution file is only possible after a problem was created\n");
return SCIP_READERROR;
}
if( SCIPgetStage(scip) == SCIP_STAGE_SOLVED )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_NORMAL, NULL,
"primal solution from solution file <%s> was ignored - problem is already solved to optimality\n",
filename);
*result = SCIP_SUCCESS;
return SCIP_OKAY;
}
/* open input file in order to determine type */
file = SCIPfopen(filename, "r");
if( file == NULL )
{
SCIPerrorMessage("cannot open file <%s> for reading\n", filename);
SCIPprintSysError(filename);
return SCIP_NOFILE;
}
/* get next line */
if( SCIPfgets(buffer, (int) sizeof(buffer), file) == NULL )
{
SCIPerrorMessage("cannot parse file.\n");
return SCIP_READERROR;
}
/* close file */
SCIPfclose(file);
/* decide whether it is xml */
s = buffer;
/* skip spaces */
while( isspace((unsigned char)*s) )
++s;
if( s[0] == '<' && s[1] == '?' && s[2] == 'x' && s[3] == 'm' && s[4] == 'l' )
{
/* read XML solution and add it to the solution pool */
SCIP_CALL( readXMLSol(scip, filename) );
}
else
{
/* read the solution and add it to the solution pool */
SCIP_CALL( readSol(scip, filename) );
}
*result = SCIP_SUCCESS;
return SCIP_OKAY;
}