/**Clean cut 2, different algorithm. First check the dynamic of the cut if < maxRatio scale to a biggest coef of 1
otherwise scale it so that biggest coeff is 1 and try removing tinys ( < 1/maxRatio) either succeed or fail */
int
Validator::cleanCut2(OsiRowCut & aCut, const double * solCut, const OsiSolverInterface &si, const CglParam &/* par */,
const double * origColLower, const double * origColUpper) const
{
/** Compute fill-in in si */
int numcols = si.getNumCols();
// int numrows = si.getNumRows();
const double * colLower = (origColLower) ? origColLower : si.getColLower();
const double * colUpper = (origColUpper) ? origColUpper : si.getColUpper();
int maxNnz = static_cast<int> ( maxFillIn_ * static_cast<double> (numcols));
double rhs = aCut.lb();
assert (aCut.ub()> 1e50);
CoinPackedVector *vec = const_cast<CoinPackedVector *>(&aCut.row());
// vec->sortIncrIndex();
int * indices = vec->getIndices();
double * elems = vec->getElements();
int n = vec->getNumElements();
if (n==0)
{
numRejected_[EmptyCut]++;
return EmptyCut;
}
/** First compute violation if it is too small exit */
double violation = aCut.violated(solCut);
if (violation < minViolation_)
return 1;
/** Now relax get dynamic and remove tiny elements */
int offset = 0;
rhs -= 1e-10;
double smallest = fabs(rhs);
double biggest = smallest;
double veryTiny = 1e-20;
for (int i = 0 ; i < n ; i++)
{
double val = fabs(elems[i]);
if (val > veryTiny) //tiny should be very very small
{
smallest = std::min(val,smallest);
biggest = std::max (val,biggest);
}
}
if (biggest > 1e9)
{
#ifdef DEBUG
std::cout<<"Whaooo "<<biggest/smallest<<std::endl;
#endif
numRejected_[BigDynamic]++;
return BigDynamic;
}
//rescale the cut so that biggest is 1e1.
double toBeBiggest = rhsScale_;
rhs *= (toBeBiggest / biggest);
toBeBiggest /= biggest;
for (int i = 0 ; i < n ; i++)
{
elems[i] *= toBeBiggest;
}
if (biggest > maxRatio_ * smallest) //we have to remove some small coefficients
{
double myTiny = biggest * toBeBiggest / maxRatio_;
veryTiny *= toBeBiggest ;
for (int i = 0 ; i < n ; i++)
{
double val = fabs(elems[i]);
if (val < myTiny)
{
if (val< veryTiny)
{
offset++;
continue;
}
int & iCol = indices[i];
if (elems[i]>0. && colUpper[iCol] < 1000.)
{
offset++;
rhs -= elems[i] * colUpper[iCol];
elems[i]=0;
}
else if (elems[i]<0. && colLower[iCol] > -1000.)
{
offset++;
rhs -= elems[i] * colLower[iCol];
elems[i]=0.;
}
else
{
numRejected_[SmallCoefficient]++;
return SmallCoefficient;
}
}
else //Not a small coefficient keep it
{
if (offset) //if offset is zero current values are ok
{
int i2 = i - offset;
indices[i2] = indices[i];
elems[i2] = elems[i];
}
}
}
}
if ((n - offset) > maxNnz)
{
numRejected_[DenseCut] ++;
return DenseCut;
}
if (offset)
vec->truncate(n - offset);
if (vec->getNumElements() == 0 )
{
numRejected_[EmptyCut]++;
return EmptyCut;
}
/** recheck violation */
aCut.setLb(rhs);
violation = aCut.violated(solCut);
if (violation < minViolation_)
{
numRejected_[SmallViolation]++;
return SmallViolation;
}
assert(fabs(rhs)<1e09);
return NoneAccepted;
}
/** Clean an OsiCut
\return 1 if min violation is too small
\return 2 if small coefficient can not be removed
\return 3 if dynamic is too big
\return 4 if too many non zero element*/
int
Validator::cleanCut(OsiRowCut & aCut, const double * solCut, const OsiSolverInterface &si, const CglParam& par,
const double * origColLower, const double * origColUpper) const
{
/** Compute fill-in in si */
int numcols = si.getNumCols();
const double * colLower = (origColLower) ? origColLower : si.getColLower();
const double * colUpper = (origColUpper) ? origColUpper : si.getColUpper();
int maxNnz = static_cast<int> (maxFillIn_ * static_cast<double> (numcols));
double rhs = aCut.lb();
assert (aCut.ub()> 1e50);
CoinPackedVector *vec = const_cast<CoinPackedVector *>(&aCut.row());
int * indices = vec->getIndices();
double * elems = vec->getElements();
int n = vec->getNumElements();
/** First compute violation if it is too small exit */
double violation = aCut.violated(solCut);
if (violation < minViolation_)
return 1;
/** Now relax get dynamic and remove tiny elements */
int offset = 0;
rhs -= 1e-8;
double smallest = 1e100;
double biggest = 0;
for (int i = 0 ; i < n ; i++)
{
double val = fabs(elems[i]);
if (val <= par.getEPS()) //try to remove coef
{
if (val>0 && val<1e-20)
{
offset++;
continue;
throw;
}
if (val==0)
{
offset++;
continue;
}
int & iCol = indices[i];
if (elems[i]>0. && colUpper[iCol] < 10000.)
{
offset++;
rhs -= elems[i] * colUpper[iCol];
elems[i]=0;
}
else if (elems[i]<0. && colLower[iCol] > -10000.)
{
offset++;
rhs -= elems[i] * colLower[iCol];
elems[i]=0.;
}
else
{
#ifdef DEBUG
std::cout<<"Small coefficient : "<<elems[i]<<" bounds : ["<<colLower[iCol]<<", "<<colUpper[iCol]<<std::endl;
#endif
numRejected_[SmallCoefficient]++;
return SmallCoefficient;
}
}
else //Not a small coefficient keep it
{
smallest = std::min(val,smallest);
biggest = std::max (val,biggest);
if (biggest > maxRatio_ * smallest)
{
#ifdef DEBUG
std::cout<<"Whaooo "<<biggest/smallest<<std::endl;
#endif
numRejected_[BigDynamic]++;
return BigDynamic;
}
if (offset) //if offset is zero current values are ok otherwise translate
{
int i2 = i - offset;
indices[i2] = indices[i];
elems[i2] = elems[i];
}
}
}
if ((n - offset) > maxNnz)
{
numRejected_[DenseCut] ++;
return DenseCut;
}
if (offset == n)
{
numRejected_[EmptyCut]++;
return EmptyCut;
}
if (offset)
vec->truncate(n - offset);
indices = vec->getIndices();
elems = vec->getElements();
n = vec->getNumElements();
aCut.setLb(rhs);
violation = aCut.violated(solCut);
if (violation < minViolation_)
{
numRejected_[SmallViolation]++;
return SmallViolation;
}
return NoneAccepted;
}
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;
}
