C#. Кто-нибудь знает, какие методы программирования здесь используются?

[Real Agrail]

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;
using System.Threading;

namespace sinker_on_spring
{
    public partial class FormMain : Form
    {
        System.Drawing.Graphics gr;         
        System.Drawing.SolidBrush myBrush;  
        System.Drawing.Pen myPen;          
        System.Drawing.Font drawFont;       
        int midX;          
        int midY;
        int yy, kk;         
        double koef;       
        DataTable dt;      
        Thread thr;        
        bool Start;         
        double m, k, betta;     
        double t, h;      
        int n, i, j;       
        double[] x = new double[2]; 
        double[] y = new double[2];
        double[] k1 = new double[2];
        double[] k2 = new double[2];
        double[] k3 = new double[2];
        double[] k4 = new double[2];
        double[] fx = new double[2];

        double[] tt = new double[10000];   
        double[] xx = new double[10000];
        double[] vv = new double[10000];

        public FormMain()
        {
            InitializeComponent();
            gr = pBox.CreateGraphics();
            midX = pBox.Width / 2 - 50;
            midY = pBox.Height / 2 + 30;
            myBrush = new System.Drawing.SolidBrush(System.Drawing.Color.Chocolate);
            myPen = new System.Drawing.Pen(System.Drawing.Color.Black);
            drawFont = new System.Drawing.Font("Arial", 10); 
             
            dt = new DataTable();               
            dt.Columns.Add("t");        
            dt.Columns.Add("x(t)");
            dt.Columns.Add("v(t)");

            chart1.ChartAreas[0].AxisY.Interval = 0.1; 
            chart1.ChartAreas[0].AxisX.Minimum = 0;
            
      

            kk = 0;       
            Start = false;
            yy = midY - 100;

        }


        private void FormMain_FormClosed(object sender, FormClosedEventArgs e)
        {  
            if (thr != null) 
                if (thr.IsAlive)
                    thr.Abort();
        }

        private void button3_Click(object sender, EventArgs e)
        {   
            m = Convert.ToDouble(tbM.Text);    
            k = Convert.ToDouble(tbK.Text);
            betta = Convert.ToDouble(tbBetta.Text);
            x[0] = Convert.ToDouble(tbX0.Text);
            x[1] = 0;   
            RungeKutt();   

            dt.Rows.Clear();              
            for (int i = 0; i < j; i++)
                dt.Rows.Add(String.Format("{0:0.00}",tt[i]), String.Format("{0:0.0000000}",xx[i]), String.Format("{0:0.0000000}",vv[i]));

           формы DataGridView
            dataGridView1.DataSource = dt;
            DataGridViewColumn column = dataGridView1.Columns[0];
            column.Width = 40;
            column = dataGridView1.Columns[1];
            column.Width = 120;
            column = dataGridView1.Columns[2];
            column.Width = 120;
            // Рисуем график
            chart1.Series[0].Points.Clear();
            chart1.Series[1].Points.Clear();
            for (int i = 0; i < j; i++)
            {
                chart1.Series[0].Points.AddXY(tt[i], xx[i]);
                chart1.Series[1].Points.AddXY(tt[i], vv[i]);
            }
       
            button1.Enabled = true;
            koef = (pBox.Height - 110) / (Math.Abs(xx[0])+Math.Abs(xx[1]));
            kk = 0;
            Start = false;
            button1.Enabled = true;
        }

        private void Funk() 
        {
            y[0]=fx[1];
            y[1] = -betta / m * fx[1] - k / m * fx[0];
        }

        private void Shag()
        {   
            for(i=0; i<n; i++) fx[i]=x[i]; 
            Funk();
            for(i=0; i<n; i++) k1[i]=y[i];
            for(i=0; i<n; i++) fx[i]=x[i]+h*k1[i]/2;
            Funk();
            for(i=0; i<n; i++) k2[i]=y[i];
            for(i=0; i<n; i++) fx[i]=x[i]+h*k2[i]/2; 
            Funk();
            for(i=0; i<n; i++) k3[i]=y[i];
            for(i=0; i<n; i++) fx[i]=x[i]+h*k3[i]; 
            Funk();
            for(i=0; i<n; i++) k4[i]=y[i];
            for(i=0; i<n; i++) x[i]=x[i]+(h/6)*(k1[i]+2*k2[i]+2*k3[i]+k4[i]);
        }

        private void RungeKutt()
        {   
            n=2; 
            t=0; 
            h=0.01; 
            j=0;
            while ( ((Math.Abs(x[0])>0.001)||(Math.Abs(x[1])>0.001))&&(j<10000)) 
            {
                tt[j] = t;      
                xx[j] = x[0];
                vv[j] = x[1];
                Shag();         
                t = t + h;
                j = j + 1;
            }
        }
    }
}