//! What is the probability of this type assignment ?
float SPGParser::proba(Assignment a)
{
float prob = 1.0;
for(Assignment::iterator it = a.begin();
it != a.end(); it++)
prob *= proba(*it);
return prob;
}
//! Create the union with another set
Assignment Assignment::createUnion(const Assignment &rhs) const
{
Assignment a(*this);
for(Assignment::iterator it = rhs.begin();
it != rhs.end(); it++)
a.insert(*it);
return a;
}
Lexicon<ComplexType> LexiconLearner::run(vector<list<string> > &sentences, int nbIterations, float dirichletPrior, bool verbose)
{
SimpleType targetType("s", 0);
for(int i = 0; i < nbIterations; i++)
{
// /*
if(i > 0)
verbose = false;
// */
Lexicon<ComplexType> counts;
cout << "ITERATION "<<i+1<<endl;
float logLikelihood = 0;
// Parsing and counting
for(unsigned int s = 0; s < sentences.size(); s++)
{
FrameString fs(mLex, sentences[s], targetType);
if(verbose)
cout << fs.toString() << endl;
SPGParser ps(fs);
float totalProba = ps.run();
if(verbose)
cout << "Probability : "<<totalProba<<endl;
set<Assignment> as = ps.getAssignments();
for(set<Assignment>::iterator it = as.begin();
it != as.end(); it++)
{
Assignment a = *it;
float proba = ps.proba(a);
list<string>::iterator word = sentences[s].begin();
if(verbose)
cout << "Assignment (proba "<<proba<<"): "<<endl;
for(Assignment::iterator typ = a.begin();
typ != a.end(); typ++)
{
if(word != sentences[s].end())
{
if(verbose)
cout << *word << " -> "<< fs.getType(*typ).toString() << " (type id "<<*typ<<")"<<endl;
counts[*word].addCount(fs.getType(*typ), proba);
word++;
}
}
}
if(verbose)
cout << endl;
else cout << "." << flush;
logLikelihood += log(totalProba);
}
if(!verbose)
cout << endl;
// Normalizing
counts.normalize(dirichletPrior);
// Pruning
counts.pruneZeros();
cout << counts.toString();
mLex = counts;
cout << "Perplexity (before last step): "<<-logLikelihood<<endl;
}
return mLex;
}