PolyBoRi
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00001 // -*- c++ -*- 00002 //***************************************************************************** 00014 //***************************************************************************** 00015 00016 #ifndef polybori_groebner_NextSpoly_h_ 00017 #define polybori_groebner_NextSpoly_h_ 00018 00019 // include basic definitions 00020 #include "groebner_defs.h" 00021 #include "ReductionStrategy.h" 00022 00023 BEGIN_NAMESPACE_PBORIGB 00024 00030 class NextSpoly { 00031 public: 00032 00033 NextSpoly(ReductionStrategy& gen, PairStatusSet& status): 00034 m_gen(gen), m_status(status) {} 00035 00036 Polynomial operator()(const Pair& act_pair) { 00037 return compute(act_pair, act_pair.extract(m_gen)); 00038 } 00039 00040 protected: 00041 Polynomial compute(const Pair& act_pair, const Polynomial& result) { 00042 if (act_pair.getType() == IJ_PAIR) 00043 return compute(act_pair.ijPair(), result); 00044 else 00045 if (act_pair.getType() == VARIABLE_PAIR) 00046 return compute(act_pair.variablePair(), result); 00047 00048 return result; 00049 } 00050 00051 Polynomial compute(const IJPairData& ij, const Polynomial& res) { 00052 int i = ij.i, j = ij.j; 00053 replacePair(i, j); 00054 m_status.setToHasTRep(ij.i, ij.j); 00055 if ((i != ij.i) || (ij.j != j)){ 00056 m_status.setToHasTRep(i,j); 00057 return spoly(m_gen[i].p, m_gen[j].p); 00058 } 00059 return res; 00060 } 00061 00062 Polynomial compute(const VariablePairData& vp, const Polynomial& res) { 00063 m_gen(vp.i).vPairCalculated.insert(vp.v); 00064 return (!res.isZero() && (res.lead() == m_gen[vp.i].lead)? 00065 res + m_gen[vp.i].p: res); 00066 } 00067 00068 void replacePair(int& first, int& second) { 00069 MonomialSet m = 00070 m_gen.leadingTerms.divisorsOf(m_gen[first].leadExp.LCM(m_gen[second].leadExp)); 00071 00072 replacePair(m.expBegin(), m.expEnd(), first, second); 00073 } 00074 00075 template <class Iterator> 00076 void replacePair(Iterator start, Iterator finish, int& first, int& second) { 00077 std::pair<int, int> original(first, second); 00078 while(start != finish) 00079 replaceGenerators(m_gen.index(*start++), original, first, second); 00080 } 00081 00082 private: 00083 void replaceGenerators(int index, std::pair<int, int> original, 00084 int& first, int& second) const { 00085 00086 if ((index != original.first) && (index != original.second)) { 00087 replaceGenerator(index, original.first, first); 00088 replaceGenerator(index, original.second, second); 00089 } 00090 PBORI_ASSERT(first != second); 00091 } 00092 00093 void replaceGenerator(int next, int original, int& current) const { 00094 if (m_status.hasTRep(next, original) && 00095 (m_gen[current].weightedLength > m_gen[next].weightedLength) && 00096 (m_gen[next].ecart() <= m_gen[original].ecart())) 00097 current = next; 00098 } 00099 00100 ReductionStrategy& m_gen; 00101 PairStatusSet& m_status; 00102 }; 00103 00104 END_NAMESPACE_PBORIGB 00105 00106 #endif /* polybori_groebner_NextSpoly_h_ */