F4Res::F4Res(SchreyerFrame& res)
: mFrame(res),
mRing(res.ring()),
mSchreyerRes(new ResMonomialsWithComponent(res.ring().monoid())),
mHashTable(mSchreyerRes.get(), 10)
{
}
F4Res::F4Res(SchreyerFrame& res)
: mFrame(res),
mRing(res.ring()),
mSchreyerRes(new ResMonomialsWithComponent(res.ring().monoid())),
mHashTable(mSchreyerRes.get(), 10)
{
#if 0
std::cout << "hardware threads: " << std::thread::hardware_concurrency() << std::endl;
std::cout << "testing thread tasks" << std::endl;
testTasks();
std::cout << " done testing thread tasks" << std::endl;
#endif
}
double ResF4toM2Interface::setDegreeZeroMap(SchreyerFrame& C,
DMat<RingType>& result,
int slanted_degree,
int lev)
// 'result' should be previously initialized, but will be resized.
// return value: -1 means (slanted_degree, lev) is out of range, and the zero matrix was returned.
// otherwise: the fraction of non-zero elements is returned.
{
// As above, get the size of the matrix, and 'newcols'
// Now we loop through the elements of degree 'slanted_degree + lev' at level 'lev'
const RingType& R = result.ring();
if (not (lev > 0 and lev <= C.maxLevel()))
{
result.resize(0,0);
return -1;
}
assert(lev > 0 and lev <= C.maxLevel());
int degree = slanted_degree + lev;
auto& thislevel = C.level(lev);
int ncols = 0;
for (auto p=thislevel.begin(); p != thislevel.end(); ++p)
{
if (p->mDegree == degree) ncols++;
}
auto& prevlevel = C.level(lev-1);
int* newcomps = new int[prevlevel.size()];
int nrows = 0;
for (int i=0; i<prevlevel.size(); i++)
if (prevlevel[i].mDegree == degree)
newcomps[i] = nrows++;
else
newcomps[i] = -1;
result.resize(nrows, ncols);
int col = 0;
long nnonzeros = 0;
for (auto p=thislevel.begin(); p != thislevel.end(); ++p)
{
if (p->mDegree != degree) continue;
auto& f = p->mSyzygy;
auto end = poly_iter(C.ring(), f, 1);
auto i = poly_iter(C.ring(), f);
for ( ; i != end; ++i)
{
long comp = C.monoid().get_component(i.monomial());
if (newcomps[comp] >= 0)
{
R.set_from_long(result.entry(newcomps[comp], col), C.gausser().coeff_to_int(i.coefficient()));
nnonzeros++;
}
}
++col;
}
double frac_nonzero = (nrows*ncols);
frac_nonzero = static_cast<double>(nnonzeros) / frac_nonzero;
delete[] newcomps;
return frac_nonzero;
}
