C++实现光谱角分类

以下是C++实现光谱角分类的代码示例：

#include <iostream>
#include <fstream>
#include <cmath>

#define BANDS 224   //波段数
#define CLASSES 16  //类别数
#define PIXELS 10000    //像素数

using namespace std;

float spectra[PIXELS][BANDS];    //存储像素光谱数据
int labels[PIXELS];             //存储像素标签

int main() {
    ifstream fin;
    fin.open("spectra.txt");
    float mean_spectra[CLASSES][BANDS];    //存储各类别的平均光谱向量
    int train_samples[CLASSES];           //存储各类别的训练样本数量
    int i, j, k;

    //读取像素光谱数据和标签
    for (i = 0; i < PIXELS; i++) {
        for (j = 0; j < BANDS; j++) {
            fin >> spectra[i][j];
        }
        fin >> labels[i];
    }
    fin.close();

    //计算各类别的平均光谱向量
    for (i = 0; i < CLASSES; i++) {
        for (j = 0; j < BANDS; j++) {
            mean_spectra[i][j] = 0.0;
        }
        train_samples[i] = 0;
    }
    for (i = 0; i < PIXELS; i++) {
        for (j = 0; j < BANDS; j++) {
            mean_spectra[labels[i]][j] += spectra[i][j];
        }
        train_samples[labels[i]]++;
    }
    for (i = 0; i < CLASSES; i++) {
        for (j = 0; j < BANDS; j++) {
            mean_spectra[i][j] /= train_samples[i];
        }
    }

    //分类测试像素
    int test_label;
    float min_angle, angle;
    for (i = 0; i < PIXELS; i++) {
        min_angle = 180.0;
        for (j = 0; j < CLASSES; j++) {
            angle = 0.0;
            for (k = 0; k < BANDS; k++) {
                angle += mean_spectra[j][k] * spectra[i][k];
            }
            angle = acos(angle) * 180.0 / 3.1415926535;   //计算夹角
            if (angle < min_angle) {
                min_angle = angle;
                test_label = j;
            }
        }
        cout << "Pixel " << i << ": true label = " << labels[i] << ", predicted label = " << test_label << endl;
    }

    return 0;
}

该代码与C语言实现的代码基本相同，只是增加了一些C++特有的语法，如使用ifstream读取文件等。