Esempio n. 1
0
        public Lattice(model m, inference inf, dataSeq x)
        {
            _w = x.Count;
            _h = m.NTag;

            _logBel = new belief(_w, _h);

            List <dMatrix>        YYlist = new List <dMatrix>();
            List <List <double> > Ylist  = new List <List <double> >();

            inf.getYYandY(m, x, YYlist, Ylist);

            for (int i = 0; i < _w; i++)
            {
                _logBel.belState[i] = new List <double>(Ylist[i]);

                if (i > 0)
                {
                    _logBel.belEdge[i] = new dMatrix(YYlist[i]);
                }
            }

            _heuListList = new List <List <double> >();
            for (int i = 0; i < _w; i++)
            {
                _heuListList.Add(new List <double>(new double[_h]));
            }

            Viterbi _bwdViterbi = new Viterbi(_w, _h);

            for (int i = 0; i < _w; i++)
            {
                _bwdViterbi.setScores(i, Ylist[i], YYlist[i]);
            }
            List <int> tags = new List <int>();

            _bwdViterbi.runViterbi(ref tags);
            //update the viterbiHeuristicMap
            for (int i = 0; i < _w; i++)
            {
                for (int j = 0; j < _h; j++)
                {
                    double h = _bwdViterbi.getPathScore(i, j);
                    setHeuMap(i, j, h);
                }
            }

            //get zGold
            ZGold = 0;
            for (int i = 0; i < x.Count; i++)
            {
                int s = x.getTags(i);
                ZGold += Ylist[i][s];
                if (i > 0)
                {
                    int sPre = x.getTags(i - 1);
                    ZGold += YYlist[i][sPre, s];
                }
            }
        }
Esempio n. 2
0
        virtual public double getGradCRF(List <double> vecGrad, model m, dataSeq x, baseHashSet <int> idSet)
        {
            if (idSet != null)
            {
                idSet.Clear();
            }
            int nTag = m.NTag;
            //compute beliefs
            belief bel       = new belief(x.Count, nTag);
            belief belMasked = new belief(x.Count, nTag);
            //store the YY and Y
            List <dMatrix>        YYlist = new List <dMatrix>(), maskYYlist = new List <dMatrix>();
            List <List <double> > Ylist = new List <List <double> >(), maskYlist = new List <List <double> >();

            _inf.getYYandY(m, x, YYlist, Ylist, maskYYlist, maskYlist);
            _inf.getBeliefs(bel, m, x, YYlist, Ylist);
            _inf.getBeliefs(belMasked, m, x, maskYYlist, maskYlist);
            double ZGold = belMasked.Z;
            double Z = bel.Z;

            List <featureTemp> fList;

            //Loop over nodes to compute features and update the gradient
            for (int i = 0; i < x.Count; i++)
            {
                fList = _fGene.getFeatureTemp(x, i);
                foreach (featureTemp im in fList)
                {
                    for (int s = 0; s < nTag; s++)
                    {
                        int f = _fGene.getNodeFeatID(im.id, s);
                        if (idSet != null)
                        {
                            idSet.Add(f);
                        }

                        vecGrad[f] += bel.belState[i][s] * im.val;
                        vecGrad[f] -= belMasked.belState[i][s] * im.val;
                    }
                }
            }

            //Loop over edges to compute features and update the gradient
            for (int i = 1; i < x.Count; i++)
            {
                for (int s = 0; s < nTag; s++)
                {
                    for (int sPre = 0; sPre < nTag; sPre++)
                    {
                        int f = _fGene.getEdgeFeatID(sPre, s);
                        if (idSet != null)
                        {
                            idSet.Add(f);
                        }

                        vecGrad[f] += bel.belEdge[i][sPre, s];
                        vecGrad[f] -= belMasked.belEdge[i][sPre, s];
                    }
                }
            }
            return(Z - ZGold);//-log{P(y*|x,w)}
        }