Linear Regression(線性回歸)

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ConsoleApplication1

{

    class Program

    {

        static double AverageX = 0, AverageY = 0;

        static double Numerator = 0;

        static double Denominator = 0;

        static double RCB;

        static double RCA;

        static double Residual_SS = 0;

        static double Regression_SS = 0;

        static void Main(string[] args)

        {

            double[,] Point = new double[,]

            {

                {0, 67.37},

                {4, 71.0},

                {10, 76.3},

                {15, 80.6},

                {21, 85.7},

                {29, 92.9},

                {36, 99.4},

                {51, 110.6},

                {68, 126.1}

            };

            LinearRegression(Point);

            Console.Read();

        }       

        public static void LinearRegression(double[,] point)

        {

            if (point.GetLength(0) < 2)

            {

                Console.WriteLine("點的數量小於2，無法進行線性回歸");

                return;

            }           

            for (int i = 0; i < point.GetLength(0); i++)

            {

                AverageX += point[i, 0];

                AverageY += point[i, 1];

            }

            AverageX /= point.GetLength(0);

            AverageY /= point.GetLength(0);

            Console.WriteLine("平均X: {0}\n平均Y: {1}", AverageX, AverageY);          

            for (int i = 0; i < point.GetLength(0); i++)

            {

                Numerator += (point[i, 0] - AverageX) * (point[i, 1] - AverageY);

                Denominator += (point[i,0] - AverageX) * (point[i,0] - AverageX);

            }

            RCB = Numerator / Denominator;

            RCA = AverageY - RCB * AverageX;

            Console.WriteLine("回歸係數A： " + RCA.ToString("0.0000"));

            Console.WriteLine("回歸係數B： " + RCB.ToString("0.0000"));

            Console.WriteLine(string.Format("方程為： y = {0} + {1} * x",

                RCA.ToString("0.0000"), RCB.ToString("0.0000")));         

            for (int i = 0; i < point.GetLength(0); i++)

            {

                Residual_SS += (point[i, 1] - RCA - RCB * point[i, 0]) * (point[i, 1] - RCA - RCB * point[i, 0]);

                Regression_SS += (RCA + RCB * point[i, 0] - AverageY) * (RCA + RCB * point[i, 0] - AverageY);

            }

            Console.WriteLine("剩餘平方和： " + Residual_SS.ToString("0.0000"));

            Console.WriteLine("回歸平方和： " + Regression_SS.ToString("0.0000"));

        }

    }

}