diff options
author | Patrick Simianer <p@simianer.de> | 2012-03-13 09:24:47 +0100 |
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committer | Patrick Simianer <p@simianer.de> | 2012-03-13 09:24:47 +0100 |
commit | ef6085e558e26c8819f1735425761103021b6470 (patch) | |
tree | 5cf70e4c48c64d838e1326b5a505c8c4061bff4a /dpmert/mert_geometry.h | |
parent | 10a232656a0c882b3b955d2bcfac138ce11e8a2e (diff) | |
parent | dfbc278c1057555fda9312291c8024049e00b7d8 (diff) |
merge with upstream
Diffstat (limited to 'dpmert/mert_geometry.h')
-rw-r--r-- | dpmert/mert_geometry.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/dpmert/mert_geometry.h b/dpmert/mert_geometry.h new file mode 100644 index 00000000..a8b6959e --- /dev/null +++ b/dpmert/mert_geometry.h @@ -0,0 +1,81 @@ +#ifndef _MERT_GEOMETRY_H_ +#define _MERT_GEOMETRY_H_ + +#include <vector> +#include <iostream> +#include <boost/shared_ptr.hpp> + +#include "hg.h" +#include "sparse_vector.h" + +static const double kMinusInfinity = -std::numeric_limits<double>::infinity(); +static const double kPlusInfinity = std::numeric_limits<double>::infinity(); + +struct MERTPoint { + MERTPoint() : x(), m(), b(), edge() {} + MERTPoint(double _m, double _b) : + x(kMinusInfinity), m(_m), b(_b), edge() {} + MERTPoint(double _x, double _m, double _b, const boost::shared_ptr<MERTPoint>& p1_, const boost::shared_ptr<MERTPoint>& p2_) : + x(_x), m(_m), b(_b), p1(p1_), p2(p2_), edge() {} + MERTPoint(double _m, double _b, const Hypergraph::Edge& edge) : + x(kMinusInfinity), m(_m), b(_b), edge(&edge) {} + + double x; // x intersection with previous segment in env, or -inf if none + double m; // this line's slope + double b; // intercept with y-axis + + // we keep a pointer to the "parents" of this segment so we can reconstruct + // the Viterbi translation corresponding to this segment + boost::shared_ptr<MERTPoint> p1; + boost::shared_ptr<MERTPoint> p2; + + // only MERTPoints created from an edge using the ConvexHullWeightFunction + // have rules + // TRulePtr rule; + const Hypergraph::Edge* edge; + + // recursively recover the Viterbi translation that will result from setting + // the weights to origin + axis * x, where x is any value from this->x up + // until the next largest x in the containing ConvexHull + void ConstructTranslation(std::vector<WordID>* trans) const; + void CollectEdgesUsed(std::vector<bool>* edges_used) const; +}; + +// this is the semiring value type, +// it defines constructors for 0, 1, and the operations + and * +struct ConvexHull { + // create semiring zero + ConvexHull() : is_sorted(true) {} // zero + // for debugging: + ConvexHull(const std::vector<boost::shared_ptr<MERTPoint> >& s) : points(s) { Sort(); } + // create semiring 1 or 0 + explicit ConvexHull(int i); + ConvexHull(int n, MERTPoint* point) : is_sorted(true), points(n, boost::shared_ptr<MERTPoint>(point)) {} + const ConvexHull& operator+=(const ConvexHull& other); + const ConvexHull& operator*=(const ConvexHull& other); + bool IsMultiplicativeIdentity() const { + return size() == 1 && (points[0]->b == 0.0 && points[0]->m == 0.0) && (!points[0]->edge) && (!points[0]->p1) && (!points[0]->p2); } + const std::vector<boost::shared_ptr<MERTPoint> >& GetSortedSegs() const { + if (!is_sorted) Sort(); + return points; + } + size_t size() const { return points.size(); } + + private: + bool IsEdgeEnvelope() const { + return points.size() == 1 && points[0]->edge; } + void Sort() const; + mutable bool is_sorted; + mutable std::vector<boost::shared_ptr<MERTPoint> > points; +}; +std::ostream& operator<<(std::ostream& os, const ConvexHull& env); + +struct ConvexHullWeightFunction { + ConvexHullWeightFunction(const SparseVector<double>& ori, + const SparseVector<double>& dir) : origin(ori), direction(dir) {} + const ConvexHull operator()(const Hypergraph::Edge& e) const; + const SparseVector<double> origin; + const SparseVector<double> direction; +}; + +#endif |