Question

Least Square Lines Equation- Text File /O Suppose we have a text file (which I supplied named data.txt) that has the following table: Temperature (celsius) Resistance (ohms) 20.0 761 31.5 817 50.0 874 71.8 917 91.3 1018 Write a Java console applicatlon, that does the following: 1. Prompt the user for the name of the text file 2. Opens the text file and reads in the ordered pair data (which is stored in the text file in the format of: xxx.xxxoxx yyy.yyyy where there is a space between the numeric values and a carriage return/line feed after the last numeric value on each line). 3. While looping through the read ordered pairs, have variables for the following: 1. keep count of the number of ordered pairs processed 2. sum of the x values 3. sum of the y values 4. sum of the square of the x values 5, sum of the products of x andy 4. After the ordered palrs have been read in, close the file. 5. Compute the regression coefficients m and b for the equation of the least squares line equation, where m is the slope and b is the y-intercept. Σ xy- Σ x)(average of y) slope you can find the y-intercept by subtracting from the average of y, the product of the slope and average of x. Σχ. (Σ x)(average of x) 6. The output to the terminal screen must be: Equation of least squares line: y 3.33658x+700.82837 7. The data file named another-test.txt. should have the output to the terminal screen: Equation of least squares line: y =-0.07926x + 754.90472

please answer it in a java console application form (java GUI).

Answer 1

// Please find the required solution

import java.io.*;
import java.io.File;
import java.util.Scanner;

public class LeastSquaresLineEquation {
    public static void main(String[] args) throws IOException {

        // 1.   prompt the user name of text file
        Scanner keyBoard = new Scanner(System.in);
        System.out.print("Enter file name:");
        String fileName = keyBoard.nextLine();
        File file = new File(fileName);
        if (!file.exists()) {
            System.out.println(fileName + " not found.");
            return;
        }
        keyBoard.close();



        // 2.   open text file and read ordered pairs
        Scanner fileScanner = new Scanner(file);

        // 3.   while looping through the ordered pairs, have variables used
        int orderedPairs = 0;
        float sumX = 0, sumY = 0, sumX2 = 0, sumXY = 0;

        while (fileScanner.hasNextLine()) {
            String[] array = fileScanner.nextLine().split("\\s+");
            float x = Float.valueOf(array[0]);
            float y = Float.valueOf(array[1]);
            sumX += x;
            sumY += y;
            sumX2 += x * x;
            sumXY += x * y;
            orderedPairs++;
        }

        //  4.  After reading ordered pairs close the line
        fileScanner.close();

        //  5.  computes regression coefficients m and b
        float avgX = sumX/orderedPairs;
        float avgY = sumY/orderedPairs;
        float slope = (sumXY - (sumX*avgY))/(sumX2 - (sumX *avgX));
        float yIntercept = avgY - slope * avgX;

        //  6,7. output the equation to terminal
        System.out.printf("Equation of least square line:y= %.5f x + %.5f", slope, yIntercept);
    }
}

data.txt riit.ixi 20.0 761 31.5 817 2 50.0 874 3 71.8 917 91.3 1018

sample output:

Enter file name:data.txt Equation of least square line:y- 3.33658 x + 700.82837