/**
* Calculate a score how well NGramProfiles match each other
*
* @param another ngram profile to compare against
* @return similarity 0=exact match
*/
public float getSimilarity(NGramProfile another) {
float sum = 0;
try {
Iterator i = another.getSorted().iterator();
while (i.hasNext()) {
NGramEntry other = (NGramEntry) i.next();
if (ngrams.containsKey(other.seq)) {
sum += Math.abs((other.frequency - ((NGramEntry) ngrams.get(other.seq)).frequency)) / 2;
} else {
sum += other.frequency;
}
}
i = getSorted().iterator();
while (i.hasNext()) {
NGramEntry other = (NGramEntry) i.next();
if (another.ngrams.containsKey(other.seq)) {
sum +=
Math.abs((other.frequency - ((NGramEntry) another.ngrams.get(other.seq)).frequency))
/ 2;
} else {
sum += other.frequency;
}
}
} catch (final Exception e) {
LOGGER.warn(e);
}
return sum;
}
/**
* Create a new Language profile from (preferably quite large) text file
*
* @param name is thename of profile
* @param is is the stream to read
* @param encoding is the encoding of stream
*/
public static NGramProfile create(String name, InputStream is, String encoding) {
NGramProfile newProfile =
new NGramProfile(name, ABSOLUTE_MIN_NGRAM_LENGTH, ABSOLUTE_MAX_NGRAM_LENGTH);
BufferedInputStream bis = new BufferedInputStream(is);
byte buffer[] = new byte[4096];
StringBuffer text = new StringBuffer();
int len;
try {
while ((len = bis.read(buffer)) != -1) {
text.append(new String(buffer, 0, len, encoding));
}
} catch (final IOException e) {
LOGGER.warn("Exception raised while creating profile.", e);
}
newProfile.analyze(text);
return newProfile;
}
/**
* main method used for testing only
*
* @param args
*/
public static void main(String args[]) throws Exception {
String usage =
"Usage: NGramProfile "
+ "[-create profilename filename encoding] "
+ "[-similarity file1 file2] "
+ "[-score profile-name filename encoding]";
int command = 0;
final int CREATE = 1;
final int SIMILARITY = 2;
final int SCORE = 3;
String profilename = "";
String filename = "";
String filename2 = "";
String encoding = "";
if (args.length == 0) {
System.err.println(usage);
System.exit(-1);
}
for (int i = 0; i < args.length; i++) { // parse command line
if (args[i].equals("-create")) { // found -create option
command = CREATE;
profilename = args[++i];
filename = args[++i];
encoding = args[++i];
}
if (args[i].equals("-similarity")) { // found -similarity option
command = SIMILARITY;
filename = args[++i];
filename2 = args[++i];
encoding = args[++i];
}
if (args[i].equals("-score")) { // found -Score option
command = SCORE;
profilename = args[++i];
filename = args[++i];
encoding = args[++i];
}
}
switch (command) {
case CREATE:
File f = new File(filename);
FileInputStream fis = new FileInputStream(f);
NGramProfile newProfile = NGramProfile.create(profilename, fis, encoding);
fis.close();
f = new File(profilename + "." + FILE_EXTENSION);
FileOutputStream fos = new FileOutputStream(f);
newProfile.save(fos);
System.out.println("new profile " + profilename + "." + FILE_EXTENSION + " was created.");
break;
case SIMILARITY:
f = new File(filename);
fis = new FileInputStream(f);
newProfile = NGramProfile.create(filename, fis, encoding);
newProfile.normalize();
f = new File(filename2);
fis = new FileInputStream(f);
NGramProfile newProfile2 = NGramProfile.create(filename2, fis, encoding);
newProfile2.normalize();
System.out.println("Similarity is " + newProfile.getSimilarity(newProfile2));
break;
case SCORE:
f = new File(filename);
fis = new FileInputStream(f);
newProfile = NGramProfile.create(filename, fis, encoding);
f = new File(profilename + "." + FILE_EXTENSION);
fis = new FileInputStream(f);
NGramProfile compare =
new NGramProfile(profilename, DEFAULT_MIN_NGRAM_LENGTH, DEFAULT_MAX_NGRAM_LENGTH);
compare.load(fis);
System.out.println("Score is " + compare.getSimilarity(newProfile));
break;
}
}
