/*作者：徐朝*/
/*keystonexu@yahoo.com.cn*/
package regression.function;
import kernel.*;
//這是加法的定義
public class Addition extends Function {

	public Addition() {
		SubItems = new Program[2];
		symbol = "+";
	}

	public Object eval() 
	{
		double data1 =  ((Double)(SubItems[0].eval())).doubleValue();
		double data2 =  ((Double)(SubItems[1].eval())).doubleValue();
		return new Double(data1 + data2);
	}

}