package cc.mallet.pipe;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Iterator;
import cc.mallet.types.FeatureVectorSequence;
import cc.mallet.types.Instance;
import cc.mallet.types.LabelSequence;
/** Given instances with a FeatureVectorSequence in the data field, break up the sequence into
* the individual FeatureVectors, producing one FeatureVector per Instance. */
public class FeatureVectorSequence2FeatureVectors extends Pipe
{
final class FeatureVectorIterator implements Iterator<Instance>
{
Iterator<Instance> superIterator;
Instance superInstance;
Iterator dataSubiterator, targetSubiterator;
int count = 0;
public FeatureVectorIterator (Iterator<Instance> inputIterator) {
superInstance = inputIterator.next();
dataSubiterator = ((FeatureVectorSequence)superInstance.getData()).iterator();
targetSubiterator = ((LabelSequence)superInstance.getTarget()).iterator();
}
public Instance next () {
if (!dataSubiterator.hasNext()) {
assert (superIterator.hasNext());
superInstance = superIterator.next();
dataSubiterator = ((FeatureVectorSequence)superInstance.getData()).iterator();
targetSubiterator = ((LabelSequence)superInstance.getTarget()).iterator();
}
// We are assuming sequences don't have zero length
assert (dataSubiterator.hasNext());
assert (targetSubiterator.hasNext());
return new Instance (dataSubiterator.next(), targetSubiterator.next(),
superInstance.getSource()+" tokensequence:"+count++, null);
}
public boolean hasNext () {
return dataSubiterator.hasNext() || superIterator.hasNext();
}
public void remove () { }
}
public FeatureVectorSequence2FeatureVectors() {}
public Iterator<Instance> newIteratorFrom (Iterator<Instance> inputIterator) {
return new FeatureVectorIterator (inputIterator);
}
// Serialization
private static final long serialVersionUID = 1;
private static final int CURRENT_SERIAL_VERSION = 0;
private void writeObject (ObjectOutputStream out) throws IOException {
out.writeInt (CURRENT_SERIAL_VERSION);
}
private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException {
int version = in.readInt ();
}
}