using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace vcsKAIKI
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //---------------------------------------------------------------------------
        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            int ndata = 7;
            double[] datax= {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0};
            double[] datay= {3.0, 5.0, 7.0, 9.0, 11.0, 13.0, 15.0, 17.0};
            double aa,bb,rr;
            
            KAIKI(ndata, datax, datay, out aa, out bb, out rr);

            listBox1.Items.Add("y=a*x+b");
            listBox1.Items.Add("a=" + aa.ToString("0.000"));
            listBox1.Items.Add("b=" + bb.ToString("0.000"));
            listBox1.Items.Add("r=" + rr.ToString("0.000"));
        }

        //---------------------------------------------------------------------------
        private void KAIKI(int ndata, double[] datax, double[] datay,
                          out double aa, out double bb, out double rr)
        {
            int i;
            double x1,y1,x2,xy,xm,ym,c1,c2,c3;
            
            //回帰式：y=aa*x+bb
            x1 = 0.0 ; y1 = 0.0 ; x2 = 0.0 ; xy = 0.0;
            for(i=0;i<=ndata;i++){
                x1 = x1 + datax[i];
                y1 = y1 + datay[i];
                x2 = x2 + datax[i] * datax[i];
                xy = xy + datax[i] * datay[i];
            }
            xm = x1 / (double)(ndata + 1) ; ym = y1 / (double)(ndata + 1);
            aa = ((double)(ndata + 1) * xy - x1 * y1) / ((double)(ndata + 1) * x2 - x1 * x1);
            bb = (x2 * y1 - x1 * xy) / ((double)(ndata + 1) * x2 - x1 * x1);
            c1 = 0.0 ; c2 = 0.0 ; c3 = 0.0;
            for(i=0;i<=ndata;i++){
                c1 = c1 + (datax[i] - xm) * (datay[i] - ym);
                c2 = c2 + (datax[i] - xm) * (datax[i] - xm);
                c3 = c3 + (datay[i] - ym) * (datay[i] - ym);
            }
            rr = c1 / Math.Sqrt(c2 * c3);
        }
        //---------------------------------------------------------------------------

    }
}