/** free heuristic data */
static
SCIP_RETCODE heurdataFreeArrays(
SCIP* scip, /**< SCIP data structure */
SCIP_HEURDATA* heurdata /**< heuristic data */
)
{
assert(heurdata->memsize == 0 || heurdata->rowmeans != NULL);
assert(heurdata->memsize >= 0);
if( heurdata->memsize > 0 )
{
SCIPfreeBufferArray(scip, &heurdata->rowmeans);
SCIPfreeBufferArray(scip, &heurdata->rowvariances);
SCIPfreeBufferArray(scip, &heurdata->rowinfinitiesup);
SCIPfreeBufferArray(scip, &heurdata->rowinfinitiesdown);
heurdata->memsize = 0;
}
if( heurdata->varpossmemsize > 0 )
{
SCIP_VAR** vars;
int v;
assert(heurdata->varpossmemsize == SCIPgetNVars(scip));
vars = SCIPgetVars(scip);
for( v = heurdata->varpossmemsize - 1; v >= 0; --v )
{
SCIP_VAR* var;
var = vars[v];
assert(var != NULL);
assert(v == SCIPvarGetProbindex(var));
SCIP_CALL( SCIPdropVarEvent(scip, var, EVENT_DISTRIBUTION, heurdata->eventhdlr, NULL, heurdata->varfilterposs[v]) );
}
SCIPfreeBufferArray(scip, &heurdata->currentlbs);
SCIPfreeBufferArray(scip, &heurdata->currentubs);
SCIPfreeBufferArray(scip, &heurdata->updatedvars);
SCIPfreeBufferArray(scip, &heurdata->varposs);
SCIPfreeBufferArray(scip, &heurdata->varfilterposs);
}
/* allocate variable update event processing array storage */
heurdata->varpossmemsize = 0;
heurdata->nupdatedvars = 0;
return SCIP_OKAY;
}
/** generate point for close cut separation
*
* The constructed point is the convex combination of the point stored in set->closesol and the
* current LP solution. The convexity parameter is set->sepa_closecombvalue. If this parameter is
* 0, the point coincides with the LP solution.
*/
static
SCIP_RETCODE generateCloseCutPoint(
SCIP* scip, /**< SCIP data structure */
SCIP_SEPADATA* sepadata, /**< separator data */
SCIP_SOL** point /**< point to be generated (or NULL if unsuccessful) */
)
{
SCIP_VAR** vars;
SCIP_VAR* var;
SCIP_Real val;
SCIP_Real alpha;
SCIP_Real onealpha;
int nvars;
int i;
assert( scip != NULL );
assert( point != NULL );
*point = NULL;
if ( sepadata->sepasol == NULL )
return SCIP_OKAY;
alpha = sepadata->sepacombvalue;
if ( alpha < 0.001 )
return SCIP_OKAY;
onealpha = 1.0 - alpha;
/* create solution */
SCIP_CALL( SCIPcreateSol(scip, point, NULL) );
/* generate convex combination */
vars = SCIPgetVars(scip);
nvars = SCIPgetNVars(scip);
for (i = 0; i < nvars; ++i)
{
var = vars[i];
val = alpha * SCIPgetSolVal(scip, sepadata->sepasol, var) + onealpha * SCIPvarGetLPSol(var);
if ( ! SCIPisZero(scip, val) )
{
SCIP_CALL( SCIPsetSolVal(scip, *point, var, val) );
}
}
return SCIP_OKAY;
}
/** reads the objective section */
static
SCIP_RETCODE readObjective(
SCIP* scip, /**< SCIP data structure */
LPINPUT* lpinput /**< LP reading data */
)
{
char name[LP_MAX_LINELEN];
SCIP_VAR** vars;
SCIP_Real* coefs;
int ncoefs;
SCIP_Bool newsection;
assert(lpinput != NULL);
/* read the objective coefficients */
SCIP_CALL( readCoefficients(scip, lpinput, TRUE, name, &vars, &coefs, &ncoefs, &newsection) );
if( !hasError(lpinput) )
{
int i;
SCIP_VAR** oldvars;
/* set all linear coefficients to 0 */
oldvars = SCIPgetVars(scip);
for( i = 0; i < SCIPgetNVars(scip); i++ )
{
SCIP_CALL( SCIPchgVarObj(scip, oldvars[i], 0.0) );
}
/* set the linear objective values */
for( i = 0; i < ncoefs; ++i )
{
SCIP_CALL( SCIPchgVarObj(scip, vars[i], coefs[i]) );
}
}
/* free memory */
SCIPfreeMemoryArrayNull(scip, &vars);
SCIPfreeMemoryArrayNull(scip, &coefs);
return SCIP_OKAY;
}
/** presolving execution method */
static
SCIP_DECL_PRESOLEXEC(presolExecInttobinary)
{ /*lint --e{715}*/
SCIP_VAR** scipvars;
SCIP_VAR** vars;
int nbinvars;
int nintvars;
int v;
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
if( SCIPdoNotAggr(scip) )
return SCIP_OKAY;
/* get the problem variables */
scipvars = SCIPgetVars(scip);
nbinvars = SCIPgetNBinVars(scip);
nintvars = SCIPgetNIntVars(scip);
if( nintvars == 0 )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
/* copy the integer variables into an own array, since adding binary variables affects the left-most slots in the
* array and thereby interferes with our search loop
*/
SCIP_CALL( SCIPduplicateBufferArray(scip, &vars, &scipvars[nbinvars], nintvars) );
/* scan the integer variables for possible conversion into binaries;
* we have to collect the variables first in an own
*/
for( v = 0; v < nintvars; ++v )
{
SCIP_Real lb;
SCIP_Real ub;
assert(SCIPvarGetType(vars[v]) == SCIP_VARTYPE_INTEGER);
/* get variable's bounds */
lb = SCIPvarGetLbGlobal(vars[v]);
ub = SCIPvarGetUbGlobal(vars[v]);
/* check if bounds are exactly one apart */
if( SCIPisEQ(scip, lb, ub - 1.0) )
{
SCIP_VAR* binvar;
char binvarname[SCIP_MAXSTRLEN];
SCIP_Bool infeasible;
SCIP_Bool redundant;
SCIP_Bool aggregated;
SCIPdebugMessage("converting <%s>[%g,%g] into binary variable\n", SCIPvarGetName(vars[v]), lb, ub);
/* create binary variable */
(void) SCIPsnprintf(binvarname, SCIP_MAXSTRLEN, "%s_bin", SCIPvarGetName(vars[v]));
SCIP_CALL( SCIPcreateVar(scip, &binvar, binvarname, 0.0, 1.0, 0.0, SCIP_VARTYPE_BINARY,
SCIPvarIsInitial(vars[v]), SCIPvarIsRemovable(vars[v]), NULL, NULL, NULL, NULL, NULL) );
SCIP_CALL( SCIPaddVar(scip, binvar) );
/* aggregate integer and binary variable */
SCIP_CALL( SCIPaggregateVars(scip, vars[v], binvar, 1.0, -1.0, lb, &infeasible, &redundant, &aggregated) );
/* release binary variable */
SCIP_CALL( SCIPreleaseVar(scip, &binvar) );
/* it can be the case that this aggregation detects an infeasibility; for example, during the copy of the
* variable bounds from the integer variable to the binary variable, infeasibility can be detected; this can
* happen because an upper bound or a lower bound of such a variable bound variable was "just" changed and the
* varbound constraint handler, who would detect that infeasibility (since it was creating it from a varbound
* constraint), was called before that bound change was detected due to the presolving priorities;
*/
if( infeasible )
{
*result = SCIP_CUTOFF;
break;
}
assert(redundant);
assert(aggregated);
(*nchgvartypes)++;
*result = SCIP_SUCCESS;
}
}
/* free temporary memory */
SCIPfreeBufferArray(scip, &vars);
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;
}
/** execution method of presolver */
static
SCIP_DECL_PRESOLEXEC(presolExecDualfix)
{ /*lint --e{715}*/
SCIP_VAR** vars;
SCIP_Real bound;
SCIP_Real roundbound;
SCIP_Real obj;
SCIP_Bool infeasible;
SCIP_Bool fixed;
int nvars;
int v;
assert(presol != NULL);
assert(strcmp(SCIPpresolGetName(presol), PRESOL_NAME) == 0);
assert(result != NULL);
*result = SCIP_DIDNOTFIND;
/* 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 )
{
/* don't perform dual presolving operations on deleted variables */
if( SCIPvarIsDeleted(vars[v]) )
continue;
obj = SCIPvarGetObj(vars[v]);
/* 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(vars[v]) && SCIPvarMayRoundUp(vars[v]) )
{
bound = SCIPvarGetLbGlobal(vars[v]);
if( SCIPisLT(scip, bound, 0.0) )
{
if( SCIPisLE(scip, 0.0, SCIPvarGetUbGlobal(vars[v])) )
bound = 0.0;
else
{
/* try to take an integer value, only for polishing */
roundbound = SCIPfloor(scip, SCIPvarGetUbGlobal(vars[v]));
if( roundbound < bound )
bound = SCIPvarGetUbGlobal(vars[v]);
else
bound = roundbound;
}
}
else
{
/* try to take an integer value, only for polishing */
roundbound = SCIPceil(scip, bound);
if( roundbound < SCIPvarGetUbGlobal(vars[v]) )
bound = roundbound;
}
SCIPdebugMessage("variable <%s> with objective 0 fixed to %g\n",
SCIPvarGetName(vars[v]), bound);
}
else
{
/* if it is always possible to round variable in direction of objective value,
* fix it to its proper bound
*/
if( SCIPvarMayRoundDown(vars[v]) && !SCIPisNegative(scip, obj) )
{
bound = SCIPvarGetLbGlobal(vars[v]);
if( SCIPisZero(scip, obj) && SCIPvarGetNLocksUp(vars[v]) == 1 && SCIPisInfinity(scip, -bound) )
{
/* variable can be set to -infinity, and it 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("variable <%s> with objective %g and %d uplocks fixed to lower bound %g\n",
SCIPvarGetName(vars[v]), SCIPvarGetObj(vars[v]), SCIPvarGetNLocksUp(vars[v]), bound);
}
else if( SCIPvarMayRoundUp(vars[v]) && !SCIPisPositive(scip, obj) )
{
bound = SCIPvarGetUbGlobal(vars[v]);
if( SCIPisZero(scip, obj) && SCIPvarGetNLocksDown(vars[v]) == 1 && SCIPisInfinity(scip, bound) )
{
/* variable can be set to +infinity, and it 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("variable <%s> with objective %g and %d downlocks fixed to upper bound %g\n",
SCIPvarGetName(vars[v]), SCIPvarGetObj(vars[v]), SCIPvarGetNLocksDown(vars[v]), bound);
}
else
continue;
}
/* apply the fixing */
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(vars[v]), SCIPvarGetObj(vars[v]), bound < 0.0 ? "small" : "large");
*result = SCIP_UNBOUNDED;
return SCIP_OKAY;
}
SCIP_CALL( SCIPfixVar(scip, vars[v], bound, &infeasible, &fixed) );
if( infeasible )
{
SCIPdebugMessage(" -> infeasible fixing\n");
*result = SCIP_CUTOFF;
return SCIP_OKAY;
}
assert(fixed);
(*nfixedvars)++;
*result = SCIP_SUCCESS;
}
return SCIP_OKAY;
}
/** presolving execution method */
static
SCIP_DECL_PRESOLEXEC(presolExecBoundshift)
{ /*lint --e{715}*/
SCIP_PRESOLDATA* presoldata;
SCIP_VAR** scipvars;
SCIP_VAR** vars;
int nbinvars;
int nvars;
int v;
assert(scip != NULL);
assert(presol != NULL);
assert(strcmp(SCIPpresolGetName(presol), PRESOL_NAME) == 0);
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
/* get presolver data */
presoldata = SCIPpresolGetData(presol);
assert(presoldata != NULL);
/* get the problem variables */
scipvars = SCIPgetVars(scip);
nbinvars = SCIPgetNBinVars(scip);
nvars = SCIPgetNVars(scip) - nbinvars;
if( nvars == 0 )
return SCIP_OKAY;
if( SCIPdoNotAggr(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
/* copy the integer variables into an own array, since adding new integer variables affects the left-most slots in
* the array and thereby interferes with our search loop
*/
SCIP_CALL( SCIPduplicateBufferArray(scip, &vars, &scipvars[nbinvars], nvars) );
/* scan the integer, implicit, and continuous variables for possible conversion */
for( v = nvars - 1; v >= 0; --v )
{
SCIP_VAR* var = vars[v];
SCIP_Real lb;
SCIP_Real ub;
assert(SCIPvarGetType(var) != SCIP_VARTYPE_BINARY);
/* get current variable's bounds */
lb = SCIPvarGetLbGlobal(var);
ub = SCIPvarGetUbGlobal(var);
assert( SCIPisLE(scip, lb, ub) );
if( SCIPisEQ(scip, lb, ub) )
continue;
if( presoldata->integer && !SCIPisIntegral(scip, ub - lb) )
continue;
/* check if bounds are shiftable */
if( !SCIPisEQ(scip, lb, 0.0) && /* lower bound != 0.0 */
SCIPisLT(scip, ub, SCIPinfinity(scip)) && /* upper bound != infinity */
SCIPisGT(scip, lb, -SCIPinfinity(scip)) && /* lower bound != -infinity */
#if 0
SCIPisLT(scip, ub - lb, SCIPinfinity(scip)) && /* interval length less than SCIPinfinity(scip) */
#endif
SCIPisLT(scip, ub - lb, (SCIP_Real) presoldata->maxshift) ) /* less than max shifting */
{
SCIP_VAR* newvar;
char newvarname[SCIP_MAXSTRLEN];
SCIP_Bool infeasible;
SCIP_Bool redundant;
SCIP_Bool aggregated;
SCIPdebugMessage("convert range <%s>[%g,%g] to [%g,%g]\n", SCIPvarGetName(var), lb, ub, 0.0, (ub - lb) );
/* create new variable */
(void) SCIPsnprintf(newvarname, SCIP_MAXSTRLEN, "%s_shift", SCIPvarGetName(var));
SCIP_CALL( SCIPcreateVar(scip, &newvar, newvarname, 0.0, (ub - lb), 0.0, SCIPvarGetType(var),
SCIPvarIsInitial(var), SCIPvarIsRemovable(var), NULL, NULL, NULL, NULL, NULL) );
SCIP_CALL( SCIPaddVar(scip, newvar) );
/* aggregate old variable with new variable */
if( presoldata->flipping )
{
if( REALABS(ub) < REALABS(lb) )
{
SCIP_CALL( SCIPaggregateVars(scip, var, newvar, 1.0, 1.0, ub, &infeasible, &redundant, &aggregated) );
}
else
{
SCIP_CALL( SCIPaggregateVars(scip, var, newvar, 1.0, -1.0, lb, &infeasible, &redundant, &aggregated) );
}
}
else
{
SCIP_CALL( SCIPaggregateVars(scip, var, newvar, 1.0, -1.0, lb, &infeasible, &redundant, &aggregated) );
}
assert(!infeasible);
assert(redundant);
assert(aggregated);
SCIPdebugMessage("var <%s> with bounds [%f,%f] has obj %f\n",
SCIPvarGetName(newvar),SCIPvarGetLbGlobal(newvar),SCIPvarGetUbGlobal(newvar),SCIPvarGetObj(newvar));
/* release variable */
SCIP_CALL( SCIPreleaseVar(scip, &newvar) );
/* take care of statistic */
(*naggrvars)++;
*result = SCIP_SUCCESS;
}
}
/* free temporary memory */
SCIPfreeBufferArray(scip, &vars);
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;
}
/** presolving execution method */
static
SCIP_DECL_PRESOLEXEC(presolExecTrivial)
{ /*lint --e{715}*/
SCIP_VAR** vars;
int nvars;
int v;
assert(result != NULL);
*result = SCIP_DIDNOTFIND;
/* get the problem variables */
vars = SCIPgetVars(scip);
nvars = SCIPgetNVars(scip);
/* scan the variables for trivial bound reductions
* (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_Real lb;
SCIP_Real ub;
SCIP_Bool infeasible;
SCIP_Bool fixed;
/* get variable's bounds */
lb = SCIPvarGetLbGlobal(vars[v]);
ub = SCIPvarGetUbGlobal(vars[v]);
/* is variable integral? */
if( SCIPvarGetType(vars[v]) != SCIP_VARTYPE_CONTINUOUS )
{
SCIP_Real newlb;
SCIP_Real newub;
/* round fractional bounds on integer variables */
newlb = SCIPfeasCeil(scip, lb);
newub = SCIPfeasFloor(scip, ub);
/* check bounds on variable for infeasibility */
if( newlb > newub + 0.5 )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_NORMAL, NULL,
"problem infeasible: integral variable <%s> has bounds [%.17f,%.17f] rounded to [%.17f,%.17f]\n",
SCIPvarGetName(vars[v]), lb, ub, newlb, newub);
*result = SCIP_CUTOFF;
return SCIP_OKAY;
}
/* fix variables with equal bounds */
if( newlb > newub - 0.5 )
{
SCIPdebugMessage("fixing integral variable <%s>: [%.17f,%.17f] -> [%.17f,%.17f]\n",
SCIPvarGetName(vars[v]), lb, ub, newlb, newub);
SCIP_CALL( SCIPfixVar(scip, vars[v], newlb, &infeasible, &fixed) );
if( infeasible )
{
SCIPdebugMessage(" -> infeasible fixing\n");
*result = SCIP_CUTOFF;
return SCIP_OKAY;
}
assert(fixed);
(*nfixedvars)++;
}
else
{
/* round fractional bounds */
if( !SCIPisFeasEQ(scip, lb, newlb) )
{
SCIPdebugMessage("rounding lower bound of integral variable <%s>: [%.17f,%.17f] -> [%.17f,%.17f]\n",
SCIPvarGetName(vars[v]), lb, ub, newlb, ub);
SCIP_CALL( SCIPchgVarLb(scip, vars[v], newlb) );
(*nchgbds)++;
}
if( !SCIPisFeasEQ(scip, ub, newub) )
{
SCIPdebugMessage("rounding upper bound of integral variable <%s>: [%.17f,%.17f] -> [%.17f,%.17f]\n",
SCIPvarGetName(vars[v]), newlb, ub, newlb, newub);
SCIP_CALL( SCIPchgVarUb(scip, vars[v], newub) );
(*nchgbds)++;
}
}
}
else
{
/* check bounds on continuous variable for infeasibility */
if( SCIPisFeasGT(scip, lb, ub) )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_NORMAL, NULL,
"problem infeasible: continuous variable <%s> has bounds [%.17f,%.17f]\n",
SCIPvarGetName(vars[v]), lb, ub);
*result = SCIP_CUTOFF;
return SCIP_OKAY;
}
/* fix variables with equal bounds */
if( SCIPisEQ(scip, lb, ub) )
{
SCIP_Real fixval;
#ifdef FIXSIMPLEVALUE
fixval = SCIPselectSimpleValue(lb - 0.9 * SCIPepsilon(scip), ub + 0.9 * SCIPepsilon(scip), MAXDNOM);
#else
fixval = (lb + ub)/2;
#endif
SCIPdebugMessage("fixing continuous variable <%s>[%.17f,%.17f] to %.17f\n",
SCIPvarGetName(vars[v]), lb, ub, fixval);
SCIP_CALL( SCIPfixVar(scip, vars[v], fixval, &infeasible, &fixed) );
if( infeasible )
{
SCIPdebugMessage(" -> infeasible fixing\n");
*result = SCIP_CUTOFF;
return SCIP_OKAY;
}
assert(fixed);
(*nfixedvars)++;
}
}
}
return SCIP_OKAY;
}
/** avoid to generate columns which are fixed to zero; therefore add for each variable which is fixed to zero a
* corresponding logicor constraint to forbid this column
*
* @note variable which are fixed locally to zero should not be generated again by the pricing MIP
*/
static
SCIP_RETCODE addFixedVarsConss(
SCIP* scip, /**< SCIP data structure */
SCIP* subscip, /**< pricing SCIP data structure */
SCIP_VAR** vars, /**< variable array of the subscuip */
SCIP_CONS** conss, /**< array of setppc constraint for each item one */
int nitems /**< number of items */
)
{
SCIP_VAR** origvars;
int norigvars;
SCIP_CONS* cons;
int* consids;
int nconsids;
int consid;
int nvars;
SCIP_VAR** logicorvars;
SCIP_VAR* var;
SCIP_VARDATA* vardata;
SCIP_Bool needed;
int nlogicorvars;
int v;
int c;
int o;
/* collect all variable which are currently existing */
origvars = SCIPgetVars(scip);
norigvars = SCIPgetNVars(scip);
/* loop over all these variables and check if they are fixed to zero */
for( v = 0; v < norigvars; ++v )
{
assert(SCIPvarGetType(origvars[v]) == SCIP_VARTYPE_BINARY);
/* if the upper bound is smaller than 0.5 if follows due to the integrality that the binary variable is fixed to zero */
if( SCIPvarGetUbLocal(origvars[v]) < 0.5 )
{
SCIPdebugMessage("variable <%s> glb=[%.15g,%.15g] loc=[%.15g,%.15g] is fixed to zero\n",
SCIPvarGetName(origvars[v]), SCIPvarGetLbGlobal(origvars[v]), SCIPvarGetUbGlobal(origvars[v]),
SCIPvarGetLbLocal(origvars[v]), SCIPvarGetUbLocal(origvars[v]) );
/* coolect the constraints/items the variable belongs to */
vardata = SCIPvarGetData(origvars[v]);
nconsids = SCIPvardataGetNConsids(vardata);
consids = SCIPvardataGetConsids(vardata);
needed = TRUE;
SCIP_CALL( SCIPallocBufferArray(subscip, &logicorvars, nitems) );
nlogicorvars = 0;
consid = consids[0];
nvars = 0;
/* loop over these items and create a linear (logicor) constraint which forbids this item combination in the
* pricing problem; thereby check if this item combination is already forbidden
*/
for( c = 0, o = 0; o < nitems && needed; ++o )
{
assert(o <= consid);
cons = conss[o];
if( SCIPconsIsEnabled(cons) )
{
assert( SCIPgetNFixedonesSetppc(scip, cons) == 0 );
var = vars[nvars];
nvars++;
assert(var != NULL);
if( o == consid )
{
SCIP_CALL( SCIPgetNegatedVar(subscip, var, &var) );
}
logicorvars[nlogicorvars] = var;
nlogicorvars++;
}
else if( o == consid )
needed = FALSE;
if( o == consid )
{
c++;
if ( c == nconsids )
consid = nitems + 100;
else
{
assert(consid < consids[c]);
consid = consids[c];
}
}
}
if( needed )
{
SCIP_CALL( SCIPcreateConsBasicLogicor(subscip, &cons, SCIPvarGetName(origvars[v]), nlogicorvars, logicorvars) );
SCIP_CALL( SCIPsetConsInitial(subscip, cons, FALSE) );
SCIP_CALL( SCIPaddCons(subscip, cons) );
SCIP_CALL( SCIPreleaseCons(subscip, &cons) );
}
SCIPfreeBufferArray(subscip, &logicorvars);
}
}
return SCIP_OKAY;
}
/** execution method of primal heuristic */
static
SCIP_DECL_HEUREXEC(heurExecSimplerounding) /*lint --e{715}*/
{ /*lint --e{715}*/
SCIP_HEURDATA* heurdata;
SCIP_SOL* sol;
SCIP_VAR** lpcands;
SCIP_Real* lpcandssol;
SCIP_Longint nlps;
int nlpcands;
int c;
assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0);
assert(result != NULL);
assert(SCIPhasCurrentNodeLP(scip));
*result = SCIP_DIDNOTRUN;
/* only call heuristic, if an optimal LP solution is at hand */
if( SCIPgetLPSolstat(scip) != SCIP_LPSOLSTAT_OPTIMAL )
return SCIP_OKAY;
/* get heuristic data */
heurdata = SCIPheurGetData(heur);
assert(heurdata != NULL);
/* on our first call or after each pricing round, calculate the number of roundable variables */
if( heurdata->nroundablevars == -1 || heurtiming == SCIP_HEURTIMING_DURINGPRICINGLOOP )
{
SCIP_VAR** vars;
int nvars;
int nroundablevars;
int i;
vars = SCIPgetVars(scip);
nvars = SCIPgetNBinVars(scip) + SCIPgetNIntVars(scip);
nroundablevars = 0;
for( i = 0; i < nvars; ++i )
{
if( SCIPvarMayRoundDown(vars[i]) || SCIPvarMayRoundUp(vars[i]) )
nroundablevars++;
}
heurdata->nroundablevars = nroundablevars;
}
/* don't call heuristic if there are no roundable variables; except we are called during pricing, in this case we
* want to detect a (mixed) integer (LP) solution which is primal feasible */
if( heurdata->nroundablevars == 0 && heurtiming != SCIP_HEURTIMING_DURINGPRICINGLOOP )
return SCIP_OKAY;
/* don't call heuristic, if we have already processed the current LP solution */
nlps = SCIPgetNLPs(scip);
if( nlps == heurdata->lastlp )
return SCIP_OKAY;
heurdata->lastlp = nlps;
/* get fractional variables, that should be integral */
SCIP_CALL( SCIPgetLPBranchCands(scip, &lpcands, &lpcandssol, NULL, &nlpcands, NULL) );
/* only call heuristic, if LP solution is fractional; except we are called during pricing, in this case we
* want to detect a (mixed) integer (LP) solution which is primal feasible */
if( nlpcands == 0 && heurtiming != SCIP_HEURTIMING_DURINGPRICINGLOOP )
return SCIP_OKAY;
/* don't call heuristic, if there are more fractional variables than roundable ones */
if( nlpcands > heurdata->nroundablevars )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
SCIPdebugMessage("executing simple rounding heuristic: %d fractionals\n", nlpcands);
/* get the working solution from heuristic's local data */
sol = heurdata->sol;
assert(sol != NULL);
/* copy the current LP solution to the working solution */
SCIP_CALL( SCIPlinkLPSol(scip, sol) );
/* round all roundable fractional columns in the corresponding direction as long as no unroundable column was found */
for( c = 0; c < nlpcands; ++c )
{
SCIP_VAR* var;
SCIP_Real oldsolval;
SCIP_Real newsolval;
SCIP_Bool mayrounddown;
SCIP_Bool mayroundup;
oldsolval = lpcandssol[c];
assert(!SCIPisFeasIntegral(scip, oldsolval));
var = lpcands[c];
assert(SCIPvarGetStatus(var) == SCIP_VARSTATUS_COLUMN);
mayrounddown = SCIPvarMayRoundDown(var);
mayroundup = SCIPvarMayRoundUp(var);
SCIPdebugMessage("simple rounding heuristic: var <%s>, val=%g, rounddown=%u, roundup=%u\n",
SCIPvarGetName(var), oldsolval, mayrounddown, mayroundup);
/* choose rounding direction */
if( mayrounddown && mayroundup )
{
/* we can round in both directions: round in objective function direction */
if( SCIPvarGetObj(var) >= 0.0 )
newsolval = SCIPfeasFloor(scip, oldsolval);
else
newsolval = SCIPfeasCeil(scip, oldsolval);
}
else if( mayrounddown )
newsolval = SCIPfeasFloor(scip, oldsolval);
else if( mayroundup )
newsolval = SCIPfeasCeil(scip, oldsolval);
else
break;
/* store new solution value */
SCIP_CALL( SCIPsetSolVal(scip, sol, var, newsolval) );
}
/* check, if rounding was successful */
if( c == nlpcands )
{
SCIP_Bool stored;
/* check solution for feasibility, and add it to solution store if possible
* neither integrality nor feasibility of LP rows has to be checked, because all fractional
* variables were already moved in feasible direction to the next integer
*/
SCIP_CALL( SCIPtrySol(scip, sol, FALSE, FALSE, FALSE, FALSE, &stored) );
if( stored )
{
#ifdef SCIP_DEBUG
SCIPdebugMessage("found feasible rounded solution:\n");
SCIPprintSol(scip, sol, NULL, FALSE);
#endif
*result = SCIP_FOUNDSOL;
}
}
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;
}
/** 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;
}
