matlab 小波包生成数据利用c#画出热力图 代码实现

以下是使用 Matlab 生成小波包数据，并且使用 C# 画出热力图的代码实现：

Matlab 代码：

% 小波包生成数据
t = linspace(0, 1, 1024);
x = sin(32*pi*t) + 5 * cos(64*pi*t) + 2 * randn(size(t));
wpt = wpdec(x, 4, 'db4');

% 将小波包系数转换为矩阵
wpmtx = wp2mat(wpt);

% 保存小波包系数矩阵
save('wpmtx.mat', 'wpmtx');

C# 代码：

using System;
using System.Drawing;
using System.Windows.Forms;
using System.IO;
using System.Runtime.InteropServices;

namespace HeatMap
{
    public partial class Form1 : Form
    {
        [DllImport("kernel32.dll")]
        static extern IntPtr LoadLibrary(string lpFileName);

        [DllImport("kernel32.dll")]
        static extern bool FreeLibrary(IntPtr hModule);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        static extern int GetShortPathName(
            [MarshalAs(UnmanagedType.LPTStr)]
            string path,
            [MarshalAs(UnmanagedType.LPTStr)]
            StringBuilder shortPath,
            int shortPathLength
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr LoadLibraryEx(
            [MarshalAs(UnmanagedType.LPTStr)]
            string lpFileName,
            IntPtr hFile,
            uint dwFlags
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr LoadResource(
            IntPtr hModule,
            IntPtr hResInfo
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern IntPtr LockResource(
            IntPtr hResData
        );

        [DllImport("kernel32.dll", SetLastError = true)]
        static extern uint SizeofResource(
            IntPtr hModule,
            IntPtr hResInfo
        );

        [DllImport("user32.dll", SetLastError = true)]
        static extern IntPtr GetDC(
            IntPtr hWnd
        );

        [DllImport("user32.dll", SetLastError = true)]
        static extern int ReleaseDC(
            IntPtr hWnd,
            IntPtr hDC
        );

        [DllImport("gdi32.dll", SetLastError = true)]
        static extern IntPtr CreateCompatibleDC(
            IntPtr hDC
        );

        [DllImport("gdi32.dll", SetLastError = true)]
        static extern IntPtr CreateCompatibleBitmap(
            IntPtr hDC,
            int nWidth,
            int nHeight
        );

        [DllImport("gdi32.dll", SetLastError = true)]
        static extern IntPtr SelectObject(
            IntPtr hDC,
            IntPtr hObject
        );

        [DllImport("gdi32.dll", SetLastError = true)]
        static extern bool BitBlt(
            IntPtr hDCDest,
            int nXDest,
            int nYDest,
            int nWidth,
            int nHeight,
            IntPtr hDCSrc,
            int nXSrc,
            int nYSrc,
            uint dwRop
        );

        [DllImport("gdi32.dll", SetLastError = true)]
        static extern bool DeleteDC(
            IntPtr hDC
        );

        [DllImport("gdi32.dll", SetLastError = true)]
        static extern bool DeleteObject(
            IntPtr hObject
        );

        private const int IMAGE_BITMAP = 0;
        private const int LR_LOADFROMFILE = 0x10;
        private const int LR_CREATEDIBSECTION = 0x2000;

        private const uint SRCCOPY = 0xCC0020;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // 获取当前工作目录
            string curDir = Directory.GetCurrentDirectory();

            // 获取 Matlab Runtime 的安装目录
            string mcrDir = GetShortPathName(Path.Combine(curDir, @"mcr"));

            // 加载 Matlab Runtime 的依赖库
            LoadLibrary(Path.Combine(mcrDir, @"bin\win64\mclmcrrt8_2.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"bin\win64\mclmcr.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\kernel32.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\user32.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\gdi32.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\advapi32.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\msvcrt.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\version.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\ole32.dll"));
            LoadLibrary(Path.Combine(mcrDir, @"sys\os\win64\oleaut32.dll"));

            // 从 Matlab 生成的小波包系数矩阵文件中读取数据
            double[,] wpmtx;
            using (var reader = new BinaryReader(File.OpenRead("wpmtx.mat")))
            {
                reader.ReadChar();
                reader.ReadChar();
                reader.ReadChar();
                reader.ReadChar();
                reader.ReadChar();
                reader.ReadChar();
                reader.ReadChar();
                reader.ReadChar();
                uint version = reader.ReadUInt32();
                uint endian = reader.ReadUInt32();
                uint arrayFlags = reader.ReadUInt32();
                uint dimensions = reader.ReadUInt32();
                uint rows = reader.ReadUInt32();
                uint cols = reader.ReadUInt32();
                reader.ReadBytes(8);
                wpmtx = new double[cols, rows];
                for (int j = 0; j < rows; j++)
                {
                    for (int i = 0; i < cols; i++)
                    {
                        wpmtx[i, j] = reader.ReadDouble();
                    }
                }
            }

            // 绘制热力图
            DrawHeatmap(wpmtx);
        }

        private void DrawHeatmap(double[,] data)
        {
            // 获取绘图区域的宽度和高度
            int width = pictureBox1.Width;
            int height = pictureBox1.Height;

            // 创建 Bitmap 对象，并且设置其分辨率
            Bitmap bmp = new Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
            bmp.SetResolution(96.0f, 96.0f);

            // 创建 GDI+ 绘图对象
            Graphics g = Graphics.FromImage(bmp);

            // 获取绘图区域的句柄
            IntPtr hdc = GetDC(pictureBox1.Handle);

            // 创建兼容的 GDI 绘图对象
            IntPtr hdcMem = CreateCompatibleDC(hdc);

            // 创建兼容的 Bitmap 对象
            IntPtr hBitmap = bmp.GetHbitmap(Color.FromArgb(0));

            // 将 Bitmap 对象选择进 GDI 绘图对象
            SelectObject(hdcMem, hBitmap);

            // 计算数据的最大值和最小值
            double maxData = 0.0;
            double minData = 0.0;
            for (int j = 0; j < data.GetLength(1); j++)
            {
                for (int i = 0; i < data.GetLength(0); i++)
                {
                    if (data[i, j] > maxData)
                    {
                        maxData = data[i, j];
                    }
                    if (data[i, j] < minData)
                    {
                        minData = data[i, j];
                    }
                }
            }

            // 计算每个像素对应的数据值
            double[,] pixelData = new double[width, height];
            double xScale = (double)data.GetLength(0) / (double)width;
            double yScale = (double)data.GetLength(1) / (double)height;
            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    int x0 = (int)Math.Floor(x * xScale);
                    int y0 = (int)Math.Floor(y * yScale);
                    int x1 = (int)Math.Ceiling((x + 1) * xScale);
                    int y1 = (int)Math.Ceiling((y + 1) * yScale);
                    double sum = 0.0;
                    int count = 0;
                    for (int j = y0; j < y1; j++)
                    {
                        for (int i = x0; i < x1; i++)
                        {
                            if (i < data.GetLength(0) && j < data.GetLength(1))
                            {
                                sum += data[i, j];
                                count += 1;
                            }
                        }
                    }
                    pixelData[x, y] = sum / count;
                }
            }

            // 绘制热力图
            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    double value = pixelData[x, y];
                    double ratio = (value - minData) / (maxData - minData);
                    int color = (int)Math.Floor(ratio * 255.0);
                    g.FillRectangle(new SolidBrush(Color.FromArgb(255, color, color, color)), x, y, 1, 1);
                }
            }

            // 将绘制好的热力图拷贝到绘图区域
            BitBlt(hdc, 0, 0, width, height, hdcMem, 0, 0, SRCCOPY);

            // 释放资源
            DeleteObject(hBitmap);
            DeleteDC(hdcMem);
            ReleaseDC(pictureBox1.Handle, hdc);

            // 显示热力图
            pictureBox1.Image = bmp;
        }
    }
}

注意：上述代码中使用到了 Matlab Runtime，需要事先安装并且将其安装目录添加到系统 PATH 中。另外，Matlab 生成的小波包系数矩阵文件需要使用 BinaryReader 读取。