CSHARP生成一个带噪声的实时正弦信号使用Drawing绘制折线图，并使用S-G滤波进行实时处理，处理后的数据使用Drawing绘制折线图

以下是一个C#的示例代码，用于生成带噪声的正弦信号，并用S-G滤波进行实时处理，并使用Drawing绘制折线图。

using System;
using System.Drawing;
using System.Windows.Forms;

namespace SGFilterDemo
{
    public partial class Form1 : Form
    {
        private const int N = 200; // 采样点数
        private const int M = 5; // S-G滤波器的阶数
        private const int L = 21; // S-G滤波器的窗口长度
        private double[] x = new double[N]; // 原始信号
        private double[] y = new double[N]; // 滤波后的信号

        public Form1()
        {
            InitializeComponent();

            // 生成带噪声的正弦信号
            Random rand = new Random();
            for (int i = 0; i < N; i++)
            {
                double noise = rand.NextDouble() * 0.1 - 0.05; // 噪声范围在[-0.05, 0.05]
                x[i] = Math.Sin(i * Math.PI / 20) + noise;
            }

            // S-G滤波
            double[] c = SGFilter.GetCoefficients(M, L); // 获取滤波器系数
            for (int i = L / 2; i < N - L / 2; i++)
            {
                double sum = 0;
                for (int j = 0; j < L; j++)
                {
                    sum += c[j] * x[i - L / 2 + j];
                }
                y[i] = sum;
            }

            // 显示原始信号和滤波后的信号
            Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height);
            Graphics g = Graphics.FromImage(bmp);
            g.Clear(Color.White);
            Pen pen1 = new Pen(Color.Blue, 1);
            Pen pen2 = new Pen(Color.Red, 1);
            for (int i = 0; i < N - 1; i++)
            {
                int x1 = i * pictureBox1.Width / N;
                int y1 = pictureBox1.Height / 2 - (int)(x[i] * pictureBox1.Height / 2);
                int x2 = (i + 1) * pictureBox1.Width / N;
                int y2 = pictureBox1.Height / 2 - (int)(x[i + 1] * pictureBox1.Height / 2);
                g.DrawLine(pen1, x1, y1, x2, y2);
                y1 = pictureBox1.Height / 2 - (int)(y[i] * pictureBox1.Height / 2);
                y2 = pictureBox1.Height / 2 - (int)(y[i + 1] * pictureBox1.Height / 2);
                g.DrawLine(pen2, x1, y1, x2, y2);
            }
            pictureBox1.Image = bmp;
        }
    }

    // S-G滤波器类
    public static class SGFilter
    {
        // 获取S-G滤波器的系数
        public static double[] GetCoefficients(int m, int l)
        {
            double[] c = new double[l];
            double[] s = new double[l];
            double sum;
            int i, j, k;

            if (l < m + 1)
            {
                throw new ArgumentException("窗口长度应大于阶数");
            }

            for (i = 0; i < l; i++)
            {
                c[i] = 0;
                s[i] = 1;
            }

            for (i = 0; i <= m; i++)
            {
                sum = s[0];
                for (j = 1; j < l; j++)
                {
                    s[j] = s[j - 1] * (i - m + j) / j;
                    sum += s[j];
                }
                k = (int)Math.Round((double)(m - i + (l - 1) / 2));
                c[k] = s[l - 1] / sum;
            }

            return c;
        }
    }
}

在窗体上添加一个`PictureBox`控件，并将其大小设置为适当的大小，运行程序即可看到绘制的折线图。