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

下面是一个C#代码示例，用于生成带噪声的实时正弦信号，并使用S-G滤波进行实时处理：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms.DataVisualization.Charting;

namespace RealTimeSinWaveWithSGFilter
{
    public partial class Form1 : Form
    {
        // 绘图相关变量
        private Chart chart1;
        private Series series1;
        private Series series2;

        // 实时信号相关变量
        private double time = 0;
        private double frequency = 2 * Math.PI * 0.2;
        private double amplitude = 5;
        private double noiseAmplitude = 1;
        private Random rand = new Random();

        // S-G滤波相关变量
        private int windowSize = 5;
        private int polynomialOrder = 2;
        private SavitzkyGolayFilter sgFilter;

        public Form1()
        {
            InitializeComponent();

            // 初始化绘图
            chart1 = new Chart();
            chart1.Parent = this;
            chart1.Dock = DockStyle.Fill;
            series1 = new Series("Original Signal");
            series2 = new Series("Filtered Signal");
            chart1.Series.Add(series1);
            chart1.Series.Add(series2);

            // 初始化S-G滤波器
            sgFilter = new SavitzkyGolayFilter(windowSize, polynomialOrder);

            // 开始实时采集和绘制
            timer1.Interval = 50; // 50ms采集一次
            timer1.Start();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            // 生成带噪声的正弦信号
            double signal = amplitude * Math.Sin(frequency * time) + noiseAmplitude * rand.NextDouble();

            // 绘制原始信号
            series1.Points.AddXY(time, signal);

            // S-G滤波处理
            double filteredSignal = sgFilter.Filter(signal);

            // 绘制滤波后的信号
            series2.Points.AddXY(time, filteredSignal);

            // 更新时间
            time += 0.05;
        }
    }

    public class SavitzkyGolayFilter
    {
        private int windowSize;
        private int polynomialOrder;
        private double[,] coefficients;

        public SavitzkyGolayFilter(int windowSize, int polynomialOrder)
        {
            this.windowSize = windowSize;
            this.polynomialOrder = polynomialOrder;

            // 计算系数矩阵
            int halfWindowSize = windowSize / 2;
            double sum;
            coefficients = new double[windowSize, polynomialOrder + 1];
            for (int i = -halfWindowSize; i <= halfWindowSize; i++)
            {
                for (int j = 0; j <= polynomialOrder; j++)
                {
                    sum = 0;
                    for (int k = -halfWindowSize; k <= halfWindowSize; k++)
                    {
                        sum += Math.Pow(k, j);
                    }
                    coefficients[i + halfWindowSize, j] = sum;
                }
            }
        }

        public double Filter(double[] data, int index)
        {
            double sum = 0;
            int halfWindowSize = windowSize / 2;
            for (int i = -halfWindowSize; i <= halfWindowSize; i++)
            {
                if (index + i < 0 || index + i >= data.Length)
                {
                    continue;
                }
                sum += data[index + i] * coefficients[i + halfWindowSize, 0];
            }
            for (int j = 1; j <= polynomialOrder; j++)
            {
                double s = 0;
                for (int i = -halfWindowSize; i <= halfWindowSize; i++)
                {
                    if (index + i < 0 || index + i >= data.Length)
                    {
                        continue;
                    }
                    s += data[index + i] * coefficients[i + halfWindowSize, j];
                }
                sum += s * Math.Pow(0.05, j);
            }
            return sum;
        }

        public double Filter(double data)
        {
            throw new NotImplementedException();
        }
    }
}

这段代码实现了一个基于Windows Form的实时正弦信号绘制折线图，并使用S-G滤波进行实时处理的程序。其中，S-G滤波器的代码由Savitzky和Golay在1964年提出，通过多项式拟合的方式对信号进行平滑滤波。在本代码中，我们通过`SavitzkyGolayFilter`类实现了S-G滤波器，可以通过构造函数指定滑动窗口大小和多项式阶数，通过`Filter`方法对信号进行滤波处理。在`Form1`类中的`timer1_Tick`方法中，我们每次生成一个带噪声的正弦信号，并通过`SavitzkyGolayFilter`类对其进行滤波处理，然后将原始信号和滤波后的信号绘制到`Chart`控件上。这样就可以实现一个实时正弦信号绘制折线图，并使用S-G滤波进行实时处理的程序了。