// RTVector.java
// This class provides a vector for the RT cloud model.  It can be between
// a 1 vector and a 3 vector so that the same class can be used with cloud
// models of different dimensionalities.

public class RTVector {
	public RTVector(int d) {
		int i;

		vals=new double[d];
		dim=d;
		for(i=0; i<d; i++) vals[i]=0.0;
	}

	public RTVector(int d,double v[]) {
		int i;

		vals=new double[d];
		dim=d;
		for(i=0; i<d; i++) vals[i]=v[i];
	}

	public RTVector(RTVector v) {
		int i;

		vals=new double[v.dim];
		dim=v.dim;
		for(i=0; i<dim; i++) vals[i]=v.vals[i];
	}

	public int Dimension() {
		return(dim);
	}

	public double Get(int i) {
		if((i<0) || (i>=dim)) return(0.0);
		return(vals[i]);
	}

	public void Set(int i,double v) {
		if((i<0) || (i>=dim)) return;
		vals[i]=v;
	}

	public void Normalize() {
		int i;
		double mag=0;

		for(i=0; i<dim; i++) mag+=vals[i]*vals[i];
		if(mag==0.0) return;
		mag=Math.sqrt(mag);
		for(i=0; i<dim; i++) vals[i]/=mag;
	}

	public static double DistBetween(RTVector a,RTVector b) {
		int i;
		double ret=0.0;

		if(a.dim!=b.dim) return(0.0);
		for(i=0; i<a.dim; i++) ret+=(a.vals[i]-b.vals[i])*(a.vals[i]-b.vals[i]);
		return(Math.sqrt(ret));
	}

	public RTVector Add(RTVector a) {
		if(a.dim!=dim) return(null);

		RTVector ret=new RTVector(a);
		int i;

		for(i=0; i<dim; i++) {
			ret.vals[i]+=vals[i];
		}

		return(ret);
	}

	public RTVector Scale(double d) {
		RTVector ret=new RTVector(this);
		int i;

		for(i=0; i<dim; i++) {
			ret.vals[i]*=d;
		}

		return(ret);
	}

	public String toString() {
		String ret;
		int i;

		ret="RTVector : ";
		for(i=0; i<dim; i++) {
			ret=ret+vals[i]+" ";
		}
		return(ret);
	}

	private int dim;
	private double vals[];
}