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Diffstat (limited to 'training/dpmert/mert_geometry.cc')
-rw-r--r-- | training/dpmert/mert_geometry.cc | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/training/dpmert/mert_geometry.cc b/training/dpmert/mert_geometry.cc new file mode 100644 index 00000000..d6973658 --- /dev/null +++ b/training/dpmert/mert_geometry.cc @@ -0,0 +1,185 @@ +#include "mert_geometry.h" + +#include <cassert> +#include <limits> + +using namespace std; + +ConvexHull::ConvexHull(int i) { + if (i == 0) { + // do nothing - <> + } else if (i == 1) { + points.push_back(boost::shared_ptr<MERTPoint>(new MERTPoint(0, 0, 0, boost::shared_ptr<MERTPoint>(), boost::shared_ptr<MERTPoint>()))); + assert(this->IsMultiplicativeIdentity()); + } else { + cerr << "Only can create ConvexHull semiring 0 and 1 with this constructor!\n"; + abort(); + } +} + +const ConvexHull ConvexHullWeightFunction::operator()(const Hypergraph::Edge& e) const { + const double m = direction.dot(e.feature_values_); + const double b = origin.dot(e.feature_values_); + MERTPoint* point = new MERTPoint(m, b, e); + return ConvexHull(1, point); +} + +ostream& operator<<(ostream& os, const ConvexHull& env) { + os << '<'; + const vector<boost::shared_ptr<MERTPoint> >& points = env.GetSortedSegs(); + for (int i = 0; i < points.size(); ++i) + os << (i==0 ? "" : "|") << "x=" << points[i]->x << ",b=" << points[i]->b << ",m=" << points[i]->m << ",p1=" << points[i]->p1 << ",p2=" << points[i]->p2; + return os << '>'; +} + +#define ORIGINAL_MERT_IMPLEMENTATION 1 +#ifdef ORIGINAL_MERT_IMPLEMENTATION + +struct SlopeCompare { + bool operator() (const boost::shared_ptr<MERTPoint>& a, const boost::shared_ptr<MERTPoint>& b) const { + return a->m < b->m; + } +}; + +const ConvexHull& ConvexHull::operator+=(const ConvexHull& other) { + if (!other.is_sorted) other.Sort(); + if (points.empty()) { + points = other.points; + return *this; + } + is_sorted = false; + int j = points.size(); + points.resize(points.size() + other.points.size()); + for (int i = 0; i < other.points.size(); ++i) + points[j++] = other.points[i]; + assert(j == points.size()); + return *this; +} + +void ConvexHull::Sort() const { + sort(points.begin(), points.end(), SlopeCompare()); + const int k = points.size(); + int j = 0; + for (int i = 0; i < k; ++i) { + MERTPoint l = *points[i]; + l.x = kMinusInfinity; + // cerr << "m=" << l.m << endl; + if (0 < j) { + if (points[j-1]->m == l.m) { // lines are parallel + if (l.b <= points[j-1]->b) continue; + --j; + } + while(0 < j) { + l.x = (l.b - points[j-1]->b) / (points[j-1]->m - l.m); + if (points[j-1]->x < l.x) break; + --j; + } + if (0 == j) l.x = kMinusInfinity; + } + *points[j++] = l; + } + points.resize(j); + is_sorted = true; +} + +const ConvexHull& ConvexHull::operator*=(const ConvexHull& other) { + if (other.IsMultiplicativeIdentity()) { return *this; } + if (this->IsMultiplicativeIdentity()) { (*this) = other; return *this; } + + if (!is_sorted) Sort(); + if (!other.is_sorted) other.Sort(); + + if (this->IsEdgeEnvelope()) { +// if (other.size() > 1) +// cerr << *this << " (TIMES) " << other << endl; + boost::shared_ptr<MERTPoint> edge_parent = points[0]; + const double& edge_b = edge_parent->b; + const double& edge_m = edge_parent->m; + points.clear(); + for (int i = 0; i < other.points.size(); ++i) { + const MERTPoint& p = *other.points[i]; + const double m = p.m + edge_m; + const double b = p.b + edge_b; + const double& x = p.x; // x's don't change with * + points.push_back(boost::shared_ptr<MERTPoint>(new MERTPoint(x, m, b, edge_parent, other.points[i]))); + assert(points.back()->p1->edge); + } +// if (other.size() > 1) +// cerr << " = " << *this << endl; + } else { + vector<boost::shared_ptr<MERTPoint> > new_points; + int this_i = 0; + int other_i = 0; + const int this_size = points.size(); + const int other_size = other.points.size(); + double cur_x = kMinusInfinity; // moves from left to right across the + // real numbers, stopping for all inter- + // sections + double this_next_val = (1 < this_size ? points[1]->x : kPlusInfinity); + double other_next_val = (1 < other_size ? other.points[1]->x : kPlusInfinity); + while (this_i < this_size && other_i < other_size) { + const MERTPoint& this_point = *points[this_i]; + const MERTPoint& other_point= *other.points[other_i]; + const double m = this_point.m + other_point.m; + const double b = this_point.b + other_point.b; + + new_points.push_back(boost::shared_ptr<MERTPoint>(new MERTPoint(cur_x, m, b, points[this_i], other.points[other_i]))); + int comp = 0; + if (this_next_val < other_next_val) comp = -1; else + if (this_next_val > other_next_val) comp = 1; + if (0 == comp) { // the next values are equal, advance both indices + ++this_i; + ++other_i; + cur_x = this_next_val; // could be other_next_val (they're equal!) + this_next_val = (this_i+1 < this_size ? points[this_i+1]->x : kPlusInfinity); + other_next_val = (other_i+1 < other_size ? other.points[other_i+1]->x : kPlusInfinity); + } else { // advance the i with the lower x, update cur_x + if (-1 == comp) { + ++this_i; + cur_x = this_next_val; + this_next_val = (this_i+1 < this_size ? points[this_i+1]->x : kPlusInfinity); + } else { + ++other_i; + cur_x = other_next_val; + other_next_val = (other_i+1 < other_size ? other.points[other_i+1]->x : kPlusInfinity); + } + } + } + points.swap(new_points); + } + //cerr << "Multiply: result=" << (*this) << endl; + return *this; +} + +// recursively construct translation +void MERTPoint::ConstructTranslation(vector<WordID>* trans) const { + const MERTPoint* cur = this; + vector<vector<WordID> > ant_trans; + while(!cur->edge) { + ant_trans.resize(ant_trans.size() + 1); + cur->p2->ConstructTranslation(&ant_trans.back()); + cur = cur->p1.get(); + } + size_t ant_size = ant_trans.size(); + vector<const vector<WordID>*> pants(ant_size); + assert(ant_size == cur->edge->tail_nodes_.size()); + --ant_size; + for (int i = 0; i < pants.size(); ++i) pants[ant_size - i] = &ant_trans[i]; + cur->edge->rule_->ESubstitute(pants, trans); +} + +void MERTPoint::CollectEdgesUsed(std::vector<bool>* edges_used) const { + if (edge) { + assert(edge->id_ < edges_used->size()); + (*edges_used)[edge->id_] = true; + } + if (p1) p1->CollectEdgesUsed(edges_used); + if (p2) p2->CollectEdgesUsed(edges_used); +} + +#else + +// THIS IS THE NEW FASTER IMPLEMENTATION OF THE MERT SEMIRING OPERATIONS + +#endif + |