vector data structure

PointVector.java

public class PointVector implements WritableComparable<PointVector> {
    /**
     * Keep the tfIdf values of the terms of a document
     */
    private Vector<Double> data = new Vector<>();

    public PointVector(double [] values) {
        this.data = new Vector<>(values.length);
        this.data.addAll(Doubles.asList(values));
    }

    public PointVector(List<Double> values) {
        this.data = new Vector<>(values.size());
        this.data.addAll(values);
    }

    public PointVector(String [] values) {
        this.data = new Vector<>(values.length);
        for (String s: values) {
            this.data.add(Double.valueOf(s));
        }
    }

    public PointVector() {
        this.data = new Vector<>();
    }

    public double[] points() {
        return Doubles.toArray(data);
    }

    /**
     * Subtract the values of this vector from the PointVector passed as argument
     * @param subtracted
     * @return
     */
    public PointVector sub(PointVector subtracted) {
        int N = this.data.size();
        double [] vals = new double[N];
        for (int i = 0; i < N; i++) {
            vals[i] = this.data.get(i) - subtracted.get(i);
        }
        return new PointVector(vals);
    }

    public PointVector add(PointVector vec) {
        int N = this.data.size();
        double [] vals = new double[N];
        for (int i = 0; i < N; i++) {
            vals[i] = this.data.get(i) + vec.get(i);
        }
        return new PointVector(vals);
    }

    /**
     * Compute the dot product of this vector with the one passed as argument
     * @param vector
     * @return
     */
    public double dotProduct(PointVector vector) {
        int N = this.data.size();
        double sum = 0.0;
        for (int i = 0; i < N; i++) {
            sum += this.data.get(i) * vector.get(i);
        }
        return sum;
    }

    @Override
    public int compareTo(PointVector pointVector) {
        return 0;
    }

    @Override
    public void write(DataOutput dataOutput) throws IOException {
        dataOutput.writeInt(data.size());
        for (double d : data) {
            dataOutput.writeDouble(d);
        }
    }

    @Override
    public void readFields(DataInput dataInput) throws IOException {
        int s = dataInput.readInt(); // read the size of the vector
    }

    public Double get(int i) {
        return this.data.get(i);
    }

    public int size() {
        return this.data.size();
    }

    @Override
    public String toString() {
        if (data.isEmpty()) {
            return "[]";
        }
        StringBuilder sb = new StringBuilder();
        sb.append("[");
        for (double d : data) {
            sb.append(d);
            sb.append(", ");
        }
        final int pos = sb.lastIndexOf(",");
        sb.delete(pos, pos + 1);
        sb.append("]");
        return sb.toString();
    }
}