/**
* @brief interpolate lower ngram probabilty to current order
**/
static void output(string context, List <Ngram> vec_ngram, bool interpolate, StreamWriter sw)
{
int idx = -1;
for (int i = 0; i < vec_ngram.Count; i++)
{
Ngram ngram = vec_ngram[i];
if (ngram.word == "")
{
//It's context only, and no word
idx = i;
sw.WriteLine("{0}\t{1} {2}", context, ngram.alpha, ngram.lower);
break;
}
}
//if no lower prob, just cut off current n-gram
if (idx == -1)
{
return;
}
for (int i = 0; i < vec_ngram.Count; i++)
{
Ngram ngram = vec_ngram[i];
//assert there is only 1 lower ngram
if (ngram.word == "")
{
//Ignore context only
continue;
}
double lower_alpha = vec_ngram[idx].alpha;
if (interpolate)
{
ngram.alpha += ngram.lower * lower_alpha;
}
ngram.lower = lower_alpha;
sw.WriteLine("{0} {1}\t{2} {3}", ngram.word, context, ngram.alpha, ngram.lower);
}
}
static void Main(string[] args)
{
if (args.Length < 3)
{
Console.WriteLine("kn_lowern [input file] [output file] [ngram-order] [-i]");
return;
}
bool interpolate = false;
foreach (string arg in args)
{
if (arg == "-i")
{
interpolate = true;
}
}
int order = int.Parse(args[2]);
StreamReader sr = new StreamReader(args[0]);
StreamWriter sw = new StreamWriter(args[1]);
SortedDictionary <string, List <Ngram> > kv = new SortedDictionary <string, List <Ngram> >();
string strLine = null;
while ((strLine = sr.ReadLine()) != null)
{
string[] record = strLine.Split('\t');
//We only process ngram which order is the same as [ngram-order] parameter.
//If the order of ngram is the same as [ngram-order], we generate its context, otherwise, we just
//save it
int cur_order = record[0].Split().Length;
string strCorpus;
if (cur_order != order)
{
strCorpus = strLine;
}
else
{
//Convert foramt "word1 word2 ... wordN \t alpha gamm" to "word2 ... wordN \t word1 \t alpha gamma"
string[] ngrams = record[0].Split();
string p = String.Join(" ", ngrams, 1, ngrams.Length - 1);
strCorpus = p + "\t" + ngrams[0] + "\t" + record[1];
}
string[] items = strCorpus.Split('\t');
string context = items[0];
Ngram v = new Ngram();
if (items.Length == 2)
{
v.word = "";
string[] strV = items[1].Split();
v.alpha = double.Parse(strV[0]);
v.lower = double.Parse(strV[1]);
}
else if (items.Length == 3)
{
v.word = items[1];
string[] strV = items[2].Split();
v.alpha = double.Parse(strV[0]);
v.lower = double.Parse(strV[1]);
}
if (kv.ContainsKey(context) == false)
{
kv.Add(context, new List <Ngram>());
}
kv[context].Add(v);
}
sr.Close();
foreach (KeyValuePair <string, List <Ngram> > pair in kv)
{
output(pair.Key, pair.Value, interpolate, sw);
}
sw.Close();
}