stat.java

The WLAN Traffic Visualizer is a platform independent Java program providing accurate measurement of

package model;

//Copyright (C) 2008 Harald Unander, Wang Wenjuan
//
//    This file is part of WlanTV.
//
//    WlanTV is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    WlanTV is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU General Public License for more details.
//
//    You should have received a copy of the GNU General Public License
//    along with WlanTV.  If not, see <http://www.gnu.org/licenses/>.

import java.util.ArrayList;

public class Stat {
	double sdMean;
	private int min = 1000;
	private int max = -1000;
	private long sum;
	private ArrayList<Integer> list = new ArrayList<Integer>();

	public void calc(int diff) {
//		System.out.println(diff+" "+min+" "+max+" "+list.size());
		min = Math.min(min,diff);
		max = Math.max(max,diff);
		sum += diff;
		list.add(diff);
	}

	public double standardDeviation(Integer[] data) {
		long sdSum = 0;
		double totalVariance = 0;

		if (data.length==0 || data.length==1) return 0;
		for(int d: data) sdSum += d;
		sdMean = sdSum/data.length;
		for(int d: data) totalVariance += Math.pow(d-sdMean,2);
		double sd = Math.sqrt(totalVariance/(data.length-1));
//		return 1.96*sd/Math.sqrt((double)data.length);
		return sd;
	}

	public String get() {
		String s = "";
		if (list.size() > 0) {
			double SD = standardDeviation(list.toArray(new Integer[list.size()]));
			s =
				Math.round(sum/list.size())+"  "+
				min+"/"+max+"  "+
				"SD:"+String.format("%.1f",SD);
//				"95%:"+Math.round(sdMean-2*SD)+"/"+Math.round(sdMean+2*SD);
		}
		return s;
	}
}