SPxBasis::Desc::Desc(const SPxSolver& base)
{
rowstat.reSize(base.nRows());
colstat.reSize(base.nCols());
if (base.rep() == SPxSolver::ROW)
{
stat = &rowstat;
costat = &colstat;
}
else
{
assert(base.rep() == SPxSolver::COLUMN);
stat = &colstat;
costat = &rowstat;
}
assert(Desc::isConsistent());
}
void SPxSumST::setupWeights(SPxSolver& base)
{
int count;
int i;
Real x;
DVector work, delta, rowLen;
rowLen.reDim( base.nRows() );
work.reDim (base.nCols());
delta.reDim (base.nCols());
Real* wrk = work.get_ptr();
const Real* lhs = base.lhs().get_const_ptr();
const Real* rhs = base.rhs().get_const_ptr();
const Real* up = base.upper().get_const_ptr();
const Real* low = base.lower().get_const_ptr();
for (i = base.nRows(); --i >= 0;)
{
rowLen[i] = base.rowVector(i).length2();
if (lhs[i] > 0)
delta.multAdd(lhs[i] / rowLen[i], base.rowVector(i));
else if (rhs[i] < 0)
delta.multAdd(rhs[i] / rowLen[i], base.rowVector(i));
}
for (count = 0;; count++)
{
work += delta;
for (i = base.nCols(); --i >= 0;)
{
if (wrk[i] > up[i])
wrk[i] = up[i];
if (wrk[i] < low[i])
wrk[i] = low[i];
}
// std::cout << -(work * base.maxObj()) << std::endl;
if (count >= 12)
break;
delta.clear();
for (i = base.nRows(); --i >= 0;)
{
x = base.rowVector(i) * work;
if (lhs[i] > x)
delta.multAdd((lhs[i] - x) / rowLen[i], base.rowVector(i));
else if (rhs[i] < x)
delta.multAdd((rhs[i] - x) / rowLen[i], base.rowVector(i));
}
}
primal(work);
SPxVectorST::setupWeights(base);
}
// ----------------------------------------------------------------
void SPxWeightST::generate(SPxSolver& base)
{
SPxId tmpId;
forbidden.reSize(base.dim());
rowWeight.reSize(base.nRows());
colWeight.reSize(base.nCols());
rowRight.reSize (base.nRows());
colUp.reSize (base.nCols());
if (base.rep() == SPxSolver::COLUMN)
{
weight = &colWeight;
coWeight = &rowWeight;
}
else
{
weight = &rowWeight;
coWeight = &colWeight;
}
assert(weight->size() == base.coDim());
assert(coWeight->size() == base.dim());
setupWeights(base);
SPxBasis::Desc desc(base);
// desc.reSize(base.nRows(), base.nCols());
DataArray < SPxId > pref(base.nRows() + base.nCols());
initPrefs(pref, base, rowWeight, colWeight);
int i;
int deltai;
int j;
int sel;
for(i = 0; i < forbidden.size(); ++i)
forbidden[i] = 0;
if (base.rep() == SPxSolver::COLUMN)
{
i = 0;
deltai = 1;
}
else
{
i = pref.size() - 1;
deltai = -1;
}
{
int dim = base.dim();
Real max = 0;
for (; i >= 0 && i < pref.size(); i += deltai)
{
tmpId = pref[i];
const SVector& bVec = base.vector(tmpId);
sel = -1;
// column or row singleton ?
if (bVec.size() == 1)
{
int idx = bVec.index(0);
if (forbidden[idx] < 2)
{
sel = idx;
dim += (forbidden[idx] > 0) ? 1 : 0;
}
}
else
{
max = bVec.maxAbs();
int best = base.nRows();
for (j = bVec.size(); --j >= 0;)
{
Real x = bVec.value(j);
int k = bVec.index(j);
int l = base.coVector(k).size();
if (!forbidden[k] && (fabs(x) > STABLE * max) && (l < best))
{
best = l;
sel = k;
}
}
}
if (sel >= 0)
{
MSG_DEBUG(
if (pref[i].type() == SPxId::ROW_ID)
spxout << "DWEIST01 r" << base.number(pref[i]);
else
spxout << "DWEIST02 c" << base.number(pref[i]);
)
forbidden[sel] = 2;
if (base.rep() == SPxSolver::COLUMN)
setDualStatus(desc, base, pref[i]);
else
setPrimalStatus(desc, base, pref[i]);
for (j = bVec.size(); --j >= 0;)
{
Real x = bVec.value(j);
int k = bVec.index(j);
if (!forbidden[k] && (x > EPS * max || -x > EPS * max))
{
forbidden[k] = 1;
--dim;
}
}
if (--dim == 0)
{
//@ for(++i; i < pref.size(); ++i)
if (base.rep() == SPxSolver::COLUMN)
{
for (i += deltai; i >= 0 && i < pref.size(); i += deltai)
setPrimalStatus(desc, base, pref[i]);
for (i = forbidden.size(); --i >= 0;)
{
if (forbidden[i] < 2)
setDualStatus(desc, base, base.coId(i));
}
}
else
{
for (i += deltai; i >= 0 && i < pref.size(); i += deltai)
setDualStatus(desc, base, pref[i]);
for (i = forbidden.size(); --i >= 0;)
{
if (forbidden[i] < 2)
setPrimalStatus(desc, base, base.coId(i));
}
}
break;
}
}
else if (base.rep() == SPxSolver::COLUMN)
// ----------------------------------------------------------------
void SPxWeightST::generate(SPxSolver& base)
{
SPxId tmpId;
forbidden.reSize(base.dim());
rowWeight.reSize(base.nRows());
colWeight.reSize(base.nCols());
rowRight.reSize (base.nRows());
colUp.reSize (base.nCols());
if (base.rep() == SPxSolver::COLUMN)
{
weight = &colWeight;
coWeight = &rowWeight;
}
else
{
weight = &rowWeight;
coWeight = &colWeight;
}
assert(weight->size() == base.coDim());
assert(coWeight->size() == base.dim());
setupWeights(base);
SPxBasis::Desc desc(base);
// desc.reSize(base.nRows(), base.nCols());
DataArray < SPxId > pref(base.nRows() + base.nCols());
initPrefs(pref, base, rowWeight, colWeight);
int i;
int stepi;
int j;
int sel;
for(i = 0; i < base.dim(); ++i)
forbidden[i] = 0;
if (base.rep() == SPxSolver::COLUMN)
{
// in COLUMN rep we scan from beginning to end
i = 0;
stepi = 1;
}
else
{
// in ROW rep we scan from end to beginning
i = pref.size() - 1;
stepi = -1;
}
int dim = base.dim();
Real maxEntry = 0;
for (; i >= 0 && i < pref.size(); i += stepi)
{
tmpId = pref[i];
const SVector& vec = base.vector(tmpId);
sel = -1;
// column or row singleton ?
if (vec.size() == 1)
{
int idx = vec.index(0);
if (forbidden[idx] < 2)
{
sel = idx;
dim += (forbidden[idx] > 0) ? 1 : 0;
}
}
else
{
maxEntry = vec.maxAbs();
// initialize the nonzero counter
int minRowEntries = base.nRows();
// find a stable index with a sparse row/column
for (j = vec.size(); --j >= 0;)
{
Real x = vec.value(j);
int k = vec.index(j);
int nRowEntries = base.coVector(k).size();
if (!forbidden[k] && (spxAbs(x) > STABLE * maxEntry) && (nRowEntries < minRowEntries))
{
minRowEntries = nRowEntries;
sel = k;
}
}
}
// we found a valid index
if (sel >= 0)
{
MSG_DEBUG(
if (pref[i].type() == SPxId::ROW_ID)
std::cout << "DWEIST01 r" << base.number(pref[i]);
else
std::cout << "DWEIST02 c" << base.number(pref[i]);
)
forbidden[sel] = 2;
// put current column/row into basis
if (base.rep() == SPxSolver::COLUMN)
setDualStatus(desc, base, pref[i]);
else
setPrimalStatus(desc, base, pref[i]);
for (j = vec.size(); --j >= 0;)
{
Real x = vec.value(j);
int k = vec.index(j);
if (!forbidden[k] && (x > EPS * maxEntry || -x > EPS * maxEntry))
{
forbidden[k] = 1;
--dim;
}
}
if (--dim == 0)
{
//@ for(++i; i < pref.size(); ++i)
if (base.rep() == SPxSolver::COLUMN)
{
// set all remaining indeces to nonbasic status
for (i += stepi; i >= 0 && i < pref.size(); i += stepi)
setPrimalStatus(desc, base, pref[i]);
// fill up the basis wherever linear independence is assured
for (i = forbidden.size(); --i >= 0;)
{
if (forbidden[i] < 2)
setDualStatus(desc, base, base.coId(i));
}
}
else
{
for (i += stepi; i >= 0 && i < pref.size(); i += stepi)
setDualStatus(desc, base, pref[i]);
for (i = forbidden.size(); --i >= 0;)
{
if (forbidden[i] < 2)
setPrimalStatus(desc, base, base.coId(i));
}
}
break;
}
}