// DataSet2D.java

public class DataSet2D extends DataSet {
	public final static int SORT_NONE=0;
	public final static int SORT_X=1;
	public final static int SORT_Y=2;

	private int sort_order=SORT_NONE;

	public DataSet2D(int num,int incr) {
		super(num,incr);
	}

	public void SetSortOrder(int so) {
		if((so<0) || (so>2)) sort_order=SORT_NONE;
		sort_order=so;
	}

	public int GetSortOrder() {
		return(sort_order);
	}

	public void AddElement(Point2D p) {
		int i;

		switch(sort_order) {
		case SORT_NONE:
			data.addElement(p);
			break;
		case SORT_X:
			for(i=0; (i<data.size()) && (((Point2D)data.elementAt(i)).x<p.x); i++);
			if(i==data.size()-1) {
				data.addElement(p);
			} else {
				data.insertElementAt(p,i);
			}
			break;
		case SORT_Y:
			for(i=0; (i<data.size()) && (((Point2D)data.elementAt(i)).y<p.y); i++);
			if(i==data.size()-1) {
				data.addElement(p);
			} else {
				data.insertElementAt(p,i);
			}
			break;
		default:
			System.out.println("Bad sort order");
			break;
		}

	}

	public Point2D GetElement(int i) throws DataSet.DataException {
		if(i>=data.size())
			throw new DataSet.DataException("Element out of range");
		return((Point2D)data.elementAt(i));
	}

	public double Interpolate(double indep_var) throws InterpolationException {
		int i;

		if(sort_order==SORT_NONE) throw new InterpolationException("No sort order specified");
		if(sort_order==SORT_X) {
			for(i=0; (i<data.size()) && (((Point2D)data.elementAt(i)).x<indep_var); i++);
			if((i==0) || (i==data.size()) || (((Point2D)data.elementAt(i)).x<indep_var)) throw new InterpolationException("Data out of range");
			return(((Point2D)data.elementAt(i-1)).y+(((Point2D)data.elementAt(i-1)).y-((Point2D)data.elementAt(i)).y)*
				(indep_var-((Point2D)data.elementAt(i)).x)/
				(((Point2D)data.elementAt(i-1)).x-((Point2D)data.elementAt(i)).x));
		}
		if(sort_order==SORT_Y) {
			for(i=0; (i<data.size()) && (((Point2D)data.elementAt(i)).y<indep_var); i++);
			if((i==0) || (i==data.size()) || (((Point2D)data.elementAt(i)).y<indep_var)) throw new InterpolationException("Data out of range");
			return(((Point2D)data.elementAt(i-1)).x+(((Point2D)data.elementAt(i-1)).x-((Point2D)data.elementAt(i)).x)*
				(indep_var-((Point2D)data.elementAt(i)).y)/
				(((Point2D)data.elementAt(i-1)).y-((Point2D)data.elementAt(i)).y));
		}
		throw new InterpolationException("Bad sort order specified.");
	}

	public class InterpolationException extends Exception {
		public InterpolationException(String s) {
			super(s);
		}
	}
}