package work_1;

public class MathLinkedList {

	LinkedList linkedList = null;

	public MathLinkedList(LinkedList linkedList) {
		this.linkedList = linkedList;
		linkedList.resetHead();
//		System.out.println(linkedList.getCurrentNode().getData());

	}

	// 得到和
	public double getSum() {
		linkedList.resetHead();
		double sum = 0;
		do {
			sum += linkedList.getCurrentNode().getData();
		} while (linkedList.hasNextNode());
		return sum;
	}

	// 得到平均數
	public double getAverage() {
		linkedList.resetHead();
		return getSum() / linkedList.getLength();

	}

	// 得到方差
	public double getVariance() {

		double temp = 0;
		double aver = getAverage();
		linkedList.resetHead();
		do {
			temp += Math.pow((linkedList.getCurrentNode().getData() - aver), 2);
		} while (linkedList.hasNextNode());
		return temp / this.linkedList.getLength();
	}
}