public static void main(String args[]) {
PorterStemmer s = new PorterStemmer();
for (int i = 0; i < args.length; i++)
try {
InputStream in = new FileInputStream(args[i]);
byte buffer[] = new byte[1024];
int bufferLen = in.read(buffer);
int offset = 0;
s.reset();
do {
int ch;
if (offset < bufferLen) {
ch = buffer[offset++];
} else {
bufferLen = in.read(buffer);
offset = 0;
if (bufferLen < 0) ch = -1;
else ch = buffer[offset++];
}
if (Character.isLetter((char) ch)) {
s.add(Character.toLowerCase((char) ch));
continue;
}
s.stem();
System.out.print(s.toString());
s.reset();
if (ch < 0) break;
System.out.print((char) ch);
} while (true);
in.close();
} catch (IOException e) {
System.out.println((new StringBuilder("error reading ")).append(args[i]).toString());
}
}
@SuppressWarnings({"unchecked", "rawtypes"})
public List<String> getBestMatchingScore(String indexfile, String queryfile, String num)
throws IOException, ClassNotFoundException {
// try {
int count = Integer.parseInt(num);
// String cur_dir = "D:\\STS_Workspace\\IRSearch_PraneethReddyVellaboyana"; cur_dir + "\\" +
// System.out.println("!!!!!!!!!!!!!!!!"+cur_dir);
FileInputStream fileIn = new FileInputStream(IntegerConstants.cur_dir + indexfile);
ObjectInputStream in = new ObjectInputStream(fileIn);
inv_index = (TreeMap) in.readObject();
System.out.println(inv_index);
tokenCount = (TreeMap) in.readObject();
System.out.println(tokenCount);
// Total number of words in all the documents
int totalTokenCount = 0;
// Calculate the total number of tokens in the collection
for (Iterator i = tokenCount.entrySet().iterator(); i.hasNext(); ) {
Map.Entry next = (Map.Entry) i.next();
totalTokenCount = totalTokenCount + (Integer) next.getValue();
}
// average document length
Double avdl = totalTokenCount * 1.0 / tokenCount.size();
// Reading a file cur_dir + "\\" +
File qf = new File(IntegerConstants.cur_dir + queryfile);
BufferedReader bf = new BufferedReader(new FileReader(qf));
String querytext;
int queryid = 1;
while ((querytext = bf.readLine()) != null) {
String[] querywords = querytext.split(" ");
// Step1: Retrieve all inverted lists corresponding to terms in a query.
for (String word1 : querywords) {
PorterStemmer ps = new PorterStemmer();
String word = ps.stem(word1);
word = word.trim();
if (!word.equals("") && inv_index.containsKey(word)) {
query_index.put(word, inv_index.get(word));
}
}
// Step2: Compute BM25 scores for documents in the lists.
for (Iterator iterator1 = query_index.entrySet().iterator(); iterator1.hasNext(); ) {
// next contains list of files for the query word and their occurrences in each file
Map.Entry next = (Map.Entry) iterator1.next();
TreeMap indexes = (TreeMap) next.getValue();
for (Iterator iterator2 = indexes.entrySet().iterator(); iterator2.hasNext(); ) {
Map.Entry next2 = (Map.Entry) iterator2.next();
// number of words of the query in the document
int fi = (Integer) next2.getValue();
// total number of documents
int N = tokenCount.size();
// number of files the query word occurred in
int ni = indexes.size();
Double qfi = 0.0;
// Number of words in the query string
for (int i = 0; i < querywords.length; i++) {
// matching the query word with the index of the queries to count the matched and
// revelent query
if (querytext.contains(querywords[i])) {
qfi++;
}
}
// Computing K value
Double K =
IntegerConstants.k1
* ((1 - IntegerConstants.b)
+ IntegerConstants.b * (tokenCount.get(next2.getKey()) / avdl));
Double first_term =
(Math.log(
((IntegerConstants.ri + 0.5) / (IntegerConstants.R - IntegerConstants.ri + 0.5))
/ ((ni - IntegerConstants.ri + 0.5)
/ (N - ni - IntegerConstants.R + IntegerConstants.ri + 0.5))));
Double second_term = ((IntegerConstants.k1 + 1) * fi / (K + fi));
Double third_term = ((IntegerConstants.k2 + 1) * qfi / (IntegerConstants.k2 + qfi));
Double total = first_term * second_term * third_term;
if (documentScore.containsKey((String) next2.getKey())) {
Double valueToPut = total + documentScore.get((String) next2.getKey());
documentScore.put((String) next2.getKey(), valueToPut);
} else {
documentScore.put((String) next2.getKey(), total);
}
}
}
// putting all the rank in descending order using the rank
DescendingOrder comp = new DescendingOrder((TreeMap) documentScore);
// order document score
TreeMap<String, Double> list_asc = new TreeMap<String, Double>(comp);
list_asc.putAll(documentScore);
int rank = 1;
// iterating with respect to the number of fetch results(third) parameter from the method
for (Iterator itr = list_asc.entrySet().iterator(); itr.hasNext() && rank <= count; ) {
Map.Entry nx = (Map.Entry) itr.next();
// Double bmValue = (Double) nx.getValue();
// System.out.println(queryid + " Q0 " + nx.getKey() + " " + rank + " " + bmValue + "
// Praneeth");
// adding the files in the list by preserving the insertion order
queryResults.add(nx.getKey().toString());
rank++;
}
queryid++;
documentScore.clear();
query_index.clear();
}
in.close();
fileIn.close();
bf.close();
return queryResults;
}
