ExtensionManager::ExtensionManager( const std::vector<std::string>& vecKinds, CastFunction pFnCast, CreateFunction pFnCreate )
{
_vecKindFunctions_refCnt++;
// Removed by PETER, but did not understand exactly why.
// for ( int i = 0 ; i < vecKinds.size() ; i++ ) {
ExtensionManager::vecKindFunctions().push_back( FunctionPair( pFnCast, pFnCreate ) );
// }
}
// compute S polynomial for a pair
BRP sPolynomial(const Pair &pair, const IntermediateBasis &F, int n) {
FunctionPair fp = FunctionPair(pair, F, n);
if (!fp.good) {
return BRP();
}
if (pair.i < 0 ) {
// fp.g = x_i
// f = ax + b
BRP b = (fp.f)->remainder(*fp.g);
return b * *fp.g + b;
}
brMonomial f = fp.f->LT();
brMonomial g = fp.g->LT();
brMonomial lcm = f | g;
return *fp.f * (lcm ^ f ) + *fp.g * ( lcm ^ g );
}
// return true if both functions with indeces of pair are in the intermediate basis and their S polynomial should be computed
bool isGoodPair(const Pair &pair, const IntermediateBasis &F, const Pairs &B, int n) {
FunctionPair fp = FunctionPair(pair, F, n);
if (!fp.good) {
return false;
}
// both polynomials are monomials, so their S polynomial reduces to 0
if ( fp.g->size() == 1 && fp.f->size() == 1 ) {
//cout << "m ";
return false;
}
brMonomial g = fp.g->LT();
brMonomial f = fp.f->LT();
if( BRP::isRelativelyPrime(g,f) ) {
return false;
}
int i = pair.i;
int j = pair.j;
brMonomial lcm = pair.lcm;
IntermediateBasis::const_iterator end = F.end();
for(IntermediateBasis::const_iterator it = F.begin(); it != end; ++it) {
int k = it->first;
const BRP *K = &(it->second);
if(( k != i && k != j && BRP::isDivisibleBy(lcm, K->LT() ) && !inList(i,k,B,F) && !inList(j,k,B,F))) {
return false;
}
}
//cout << "good pair ";
return true;
}
