数据归一化

输入和输出文件都是以\t分割的txt文件，每一行是一组数据（xi）

例如

24         42         9         8         3         4         39         43

23         43         5         54         5          32         25         54

52        54        43        53        55        2        5        5        

对于第i行（该行的每个归一化后的数据=（初始数据-该行最小值）/（该行最大值-该行最小值））

归一化后xij = （xij-min）/（max-min）

import java.io.*;
import java.net.URI;
import java.nio.file.FileSystem;
import java.util.ArrayList;

public class Guiyihua {
    public static void main(String[] args) throws Exception {

        String oldPath = "C:\\Users\\hong\\Desktop\\electric.txt";
        String newPath = "C:\\Users\\hong\\Desktop\\new\\electric.txt";
        ArrayList<ArrayList<Double>> data =getFile(oldPath);



        double max;
        double min;
        double temp;
        double a;
        for (ArrayList<Double> datum : data) {
            max = getMax(datum);
            min = getMin(datum);
            for (int j = 0; j < datum.size(); j++) {
                temp =datum.get(j);
                a = (temp - min) / (max - min);
                datum.set(j,a);
            }
        }


        out(newPath,data);
    }

//获取ArrayList<Double> dataone中的最大值
    public static Double getMax(ArrayList<Double> dataone){
        double max = dataone.get(0);
        for (Double aDouble : dataone) {
            if (max < aDouble) {
                max = aDouble;
            }

        }
        return max;
    }
    //获取ArrayList<Double> dataone中的最小值
    public static Double getMin(ArrayList<Double> dataone){
        double min = dataone.get(0);
        for (Double aDouble : dataone) {
            if (min > aDouble) {
                min = aDouble;
            }

        }
        return min;
    }

    //读取txt文件并且写入ArrayList<ArrayList<Double>>
    private static ArrayList<ArrayList<Double>> getFile(String pathName) throws Exception {
        File file = new File(pathName);
        if (!file.exists())
            throw new RuntimeException("Not File!");
        BufferedReader br = new BufferedReader(new FileReader(file));
        String str;

        ArrayList<ArrayList<Double>> data = new ArrayList<>();
        while ((str = br.readLine()) != null) {
            ArrayList<Double> oneData = new ArrayList<>();
            String[] arr = str.split("\t");
            for (String s : arr) {
                oneData.add(Double.valueOf(s));
            }
            data.add(oneData);
        }
        return data;

    }
    //输出
    public static void out(String path,ArrayList<ArrayList<Double>> data) throws IOException {
        BufferedWriter writer = new BufferedWriter(new FileWriter(path));
        for (int i = 0; i <data.size() ; i++) {
            for (int j = 0; j < data.get(i).size(); j++) {
                writer.write(String.valueOf(data.get(i).get(j)));
                writer.write('\t');
            }

            writer.write('\n');
        }
    }
}