Bchart::
Bchart(SentRep & sentence)
: ChartBase( sentence )
{
pretermNum = 0;
heap = new EdgeHeap();
int len = sentence.length();
int i,j;
assert(len <= MAXSENTLEN);
char temp[512];
for(i = 0 ; i < len ; i++)
{
ECString wl = toLower(sentence[i].lexeme().c_str(), temp);
int val = wtoInt(wl);
sentence_[i].toInt() = val;
}
for(i = 0 ; i < MAXSENTLEN ; i++)
for(j = 0 ; j < MAXSENTLEN ; j++) curDemerits_[i][j] = 0;
initDenom();
}
double
Bchart::
parse()
{
initDenom();
alreadyPopedNum = 0;
bool haveS = false;
int locTimeout = ruleiCountTimeout_;
for (;;)
{
//check();
if( ruleiCounts_ > locTimeout || popedEdgeCount_ > poppedTimeout_)
{
if(printDebug(5)) wcerr << "Ran out of time" << endl;
break;
}
if(get_S() && !haveS)
{
// once we have found a parse, the total edes is set to edges * 3.5;
haveS = true;
if(printDebug(10)) wcerr << "Found S " << popedEdgeCount_ << endl;
popedEdgeCountAtS_ = popedEdgeCount_;
totEdgeCountAtS_ = ruleiCounts_;
int newTime = (int)(ruleiCounts_ * timeFactor);
if(newTime < ruleiCountTimeout_)
locTimeout = newTime;
}
// We keep track of number of ruleis to decide when time out on parsing.;
/* get best thing off of keylist */
Edge* edge = heap->pop();
if (!edge)
{
if(printDebug(5)) wcerr << "Nonthing on agenda" << endl;
break;
}
int stus = edge->status();
int cD = curDemerits_[edge->start()][edge->loc()];
if(edge->demerits() < cD - 5 && !haveS)
{
edge->demerits() = cD;
edge->setmerit();
heap->insert(edge);
continue;
}
if(isinf(edge->prob()) || isnan(edge->prob()) || isinf(edge->merit())
|| isnan(edge->merit()))
{
if(printDebug(5)) wcerr << "Over or underflow" << endl;
break;
}
if(alreadyPopedNum >= 400000)
{
if(printDebug(5)) wcerr << "alreadyPoped got too large" << endl;
break;
}
if(printDebug() > 10)
{
wcerr << popedEdgeCount_ << "\tPop";
if(stus == 0) wcerr << "< ";
else if(stus == 2) wcerr << ". ";
else wcerr << "> ";
wcerr << *edge << "\t" << edge->prob() << "\t" << edge->merit();
wcerr << "\t" << ruleiCounts_;
wcerr << endl;
}
popedEdgeCount_++;
alreadyPoped[alreadyPopedNum++] = edge;
if(!haveS) addToDemerits(edge);
/* and add it to chart */
//heap->check();
switch (stus)
{
case 0 : add_edge(edge, 0); break; //0 => continuing left;
case 1 : add_edge(edge, 1); break; //1 => continung right;
case 2 : addFinishedEdge(edge);
}
}
/* at this point we are done looking for edges etc. */
Item *snode = get_S();
/* No "S" node means the sentence was unparsable. */
if (!snode)
{
return badParse;
}
double ans = snode->prob();
if (ans <= 0.0L)
error(L"zero probability parse?");
/*
ans = -log2(ans);
if (ans == quiet_nan(0L))
error("log returned quiet_nan()");
*/
static double nat_log_2 = log( 2.0 );
ans = -log( ans )/ nat_log_2;
crossEntropy_ = ans;
return ans;
}
