eu.fbk.utils.math.DenseVector Maven / Gradle / Ivy
/*
* Copyright (2010) Fondazione Bruno Kessler (FBK)
*
* FBK reserves all rights in the Program as delivered.
* The Program or any portion thereof may not be reproduced
* in any form whatsoever except as provided by license
* without the written consent of FBK. A license under FBK's
* rights in the Program may be available directly from FBK.
*/
package eu.fbk.utils.math;
import eu.fbk.utils.mylibsvm.svm_node;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
import java.util.Iterator;
/**
* This class implements a dense vector.
*
* @author Claudio Giuliano
* @version %I%, %G%
* @since 1.0
*/
public class DenseVector implements Vector {
/**
* Define a static logger variable so that it references the
* Logger instance named DenseVector.
*/
static Logger logger = Logger.getLogger(DenseVector.class.getName());
//
protected float[] vector;
//
public DenseVector(int size) throws IllegalArgumentException {
if (size <= 0) {
throw new IllegalArgumentException();
}
vector = new float[size];
} // end constructor
//
public DenseVector(float[] vector) {
this.vector = vector;
} // end constructor
//
public void add(int index, float value) throws IndexOutOfBoundsException {
if (index < 0) {
throw new IndexOutOfBoundsException();
}
if (index > vector.length) {
throw new IndexOutOfBoundsException();
}
vector[index] += value;
} // end add
//
public float get(int index) throws IndexOutOfBoundsException {
//logger.info("get " + index);
if (index < 0 || index > vector.length) {
throw new IndexOutOfBoundsException();
}
return vector[index];
} // end get
//
public boolean isSparse() {
return false;
} // end isSparse
//
public boolean isDense() {
return true;
} // end isDense
//
public Vector merge(Vector v) {
if (v.isDense()) {
return mergeDense((DenseVector) v);
}
return mergeSparse((SparseVector) v);
} // end merge
//
protected Vector mergeSparse(SparseVector v) {
Vector m = new SparseVector();
for (int i = 0; i < size(); i++) {
m.add(i, get(i));
}
Iterator it2 = v.nonZeroElements();
int i = 0;
while (it2.hasNext()) {
i = it2.next();
m.add(i + v.size(), v.get(i));
} // end while
return m;
} // end mergeSparse
//
protected Vector mergeDense(DenseVector v) {
Vector m = new DenseVector(size() + v.size());
for (int i = 0; i < size(); i++) {
m.add(i, get(i));
}
for (int i = 0; i < v.size(); i++) {
m.add(i + v.size(), v.get(i));
}
return m;
} // end mergeDense
//
public boolean existsIndex(int index) {
//logger.debug("existsIndex: " + index);
if (index >= 0 && index < vector.length) {
return true;
}
return false;
} // end existsIndex
//
public void set(int index, float value) throws IndexOutOfBoundsException {
//logger.debug("set " + index + ", " + value);
if (index < 0) {
throw new IndexOutOfBoundsException();
}
if (index > vector.length) {
throw new IndexOutOfBoundsException();
}
vector[index] = value;
} // end set
//
public int size() {
return vector.length;
} // end vector.length
//
public int elementCount() {
return size();
} // end elementCount
//
public Iterator iterator() {
return new ValueIterator(vector);
} // end iterator
//
public Iterator nonZeroElements() {
return new IndexIterator(vector.length);
} // end nonZeroElements
//
public String toString(int fromIndex) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < vector.length; i++) {
if (vector[i] != 0) {
if (i > 0) {
sb.append(" ");
}
sb.append(fromIndex + i);
sb.append(":");
sb.append(vector[i]);
}
} // end while
return sb.toString();
} // end toString
//
public String toString() {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < vector.length; i++) {
if (vector[i] != 0) {
if (i > 0) {
sb.append(" ");
}
sb.append(i);
sb.append(":");
sb.append(vector[i]);
}
} // end while
return sb.toString();
} // end toString
//
public Node[] toNodeArray() {
Node[] node = new Node[vector.length];
for (int i = 0; i < vector.length; i++) {
node[i] = new Node();
node[i].index = i;
node[i].value = vector[i];
}
return node;
} // end toNodeArray
//
public Node[] toNodeArray(int fromIndex) {
Node[] node = new Node[vector.length];
for (int i = 0; i < vector.length; i++) {
node[i] = new Node();
node[i].index = fromIndex + i;
node[i].value = vector[i];
}
return node;
} // end toNodeArray
//
public svm_node[] toSvmNodeArray() {
svm_node[] node = new svm_node[vector.length];
for (int i = 0; i < vector.length; i++) {
node[i] = new svm_node();
node[i].index = i;
node[i].value = vector[i];
}
return node;
} // end toNodeArray
//
public svm_node[] toSvmNodeArray(int fromIndex) {
svm_node[] node = new svm_node[vector.length];
for (int i = 0; i < vector.length; i++) {
node[i] = new svm_node();
node[i].index = fromIndex + i;
node[i].value = vector[i];
}
return node;
} // end toNodeArray
public float[] toArray() {
return vector;
} // end toArray
//
public float dotProduct(DenseVector anotherDenseVector) {
//logger.info("dotProduct(DenseVector) " + anotherDenseVector);
float[] anotherVector = anotherDenseVector.toArray();
int len = vector.length;
if (len > anotherVector.length) {
len = anotherVector.length;
}
float d = 0;
for (int i = 0; i < len; i++) {
d += vector[i] * anotherVector[i];
}
return d;
} // end dotProduct
//
public float dotProduct(Vector anotherVector) {
//logger.info("dotProduct(Vector) " + anotherVector);
if (anotherVector.getClass() == this.getClass()) {
return dotProduct((DenseVector) anotherVector);
}
float d = 0;
int len = vector.length;
if (vector.length > anotherVector.size()) {
Iterator it = anotherVector.nonZeroElements();
while (it.hasNext()) {
int index = it.next().intValue();
d += vector[index] * anotherVector.get(index);
}
} else {
for (int i = 0; i < len; i++) {
d += vector[i] * anotherVector.get(i);
}
}
return d;
} // end dotProduct
//
public float norm() {
float norm = 0;
for (int i = 0; i < vector.length; i++) {
norm += Math.pow(vector[i], 2);
}
return (float) Math.sqrt(norm);
} // end norm
//
public void normalize() {
float norm = norm();
//logger.debug("norm before = " + norm);
// CHECK THIS!
if (norm == 0) {
return;
}
for (int i = 0; i < vector.length; i++) {
vector[i] /= norm;
}
//logger.debug("norm after = " + norm());
} // end normalize
//
class ValueIterator implements Iterator {
//
private float[] vector;
//
private int i;
//
public ValueIterator(float[] vector) {
this.vector = vector;
i = 0;
} // end constructor
//
public boolean hasNext() {
return i < vector.length;
} // end hasNext
//
public Object next() {
return new Float(vector[i++]);
} // end next
//
public void remove() {
// do nothing
} // end remove
} // end IndexIterator
//
class IndexIterator implements Iterator {
//
private int len;
//
private int i;
//
public IndexIterator(int len) {
this.len = len;
i = 0;
} // end constructor
//
public boolean hasNext() {
return i < len;
} // end hasNext
public Object next() {
return new Integer(i++);
} // end next
//
public void remove() {
// do nothing
} // end remove
} // end IndexIterator
//
public static void main(String args[]) throws Exception {
String logConfig = System.getProperty("log-config");
if (logConfig == null) {
logConfig = "log-config.txt";
}
PropertyConfigurator.configure(logConfig);
long begin = System.currentTimeMillis();
/*
DenseVector vector = new DenseVector();
// java org.fbk.it.hlt.termsim.DenseVector
int max = 50000;
for (int i=0;i © 2015 - 2025 Weber Informatics LLC | Privacy Policy