//return the gradient of -log{P(y*|x,w)} as follows: E_{P(y|x)}(F(x,y)) - F(x,y*) virtual public double getGrad(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); _inf.getBeliefs(bel, m, x, false); _inf.getBeliefs(belMasked, m, x, true); double ZGold = belMasked.Z; double Z = bel.Z; List <featureTemp> fList; for (int i = 0; i < x.Count; i++) { fList = _fGene.getFeatureTemp(x, i); for (int j = 0; j < fList.Count; j++) { featureTemp im = fList[j]; int id = im.id; double v = im.val; for (int s = 0; s < nTag; s++) { int f = _fGene.getNodeFeatID(id, s); if (idSet != null) { idSet.Add(f); } vecGrad[f] += bel.belState[i][s] * v; vecGrad[f] -= belMasked.belState[i][s] * v; } } } 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); }
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)} }