// face_detect.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include "opencv2\opencv.hpp"
#include <iostream>
using namespace std;
using namespace cv;
using namespace cv::ml;//将向量转化成图片矩阵并显示
void showImage(const Mat &data, int columns, const String &name)
{Mat bigImage;for (int i = 0; i < data.rows; ++i){bigImage.push_back(data.row(i).reshape(0, columns));}imshow(name, bigImage.t());
}//计算分类精度
float calculateAccuracyPercent(const Mat &original, const Mat &predicted)
{return 100 * (float)countNonZero(original == predicted) / predicted.rows;
}int main()
{const String filename = "E:\\opencv\\opencv\\sources\\samples\\data\\data01.xml";Mat data, labels;  //训练数据及对应标注
cout << "加载数据..." << endl;FileStorage f;if (f.open(filename, FileStorage::READ)){f["datamat"] >> data;f["labelsmat"] >> labels;f.release();}else{cerr << "文件无法打开: " << filename << endl;return 1;}data.convertTo(data, CV_32F);  //转换成float型
    labels.convertTo(labels, CV_32F);cout << "读取了 " << data.rows << "行数据" << endl;Mat data_train, data_test;Mat labels_train, labels_test;//将加载进来的数据均分成两部分，一部分用于训练，一部分用于测试for (int i = 0; i < data.rows; i++){if (i % 2 == 0){data_train.push_back(data.row(i));labels_train.push_back(labels.row(i));}else{data_test.push_back(data.row(i));labels_test.push_back(labels.row(i));}}cout << "训练数据： " << data_train.rows << "行" << endl;cout<<"测试数据："<< data_test.rows <<"行"<< endl;// 显示样本图片showImage(data_train, 28, "train data");showImage(data_test, 28, "test data");//创建分类器并设置参数Ptr<LogisticRegression> lr1 = LogisticRegression::create();  lr1->setLearningRate(0.001);lr1->setIterations(10);lr1->setRegularization(LogisticRegression::REG_L2);lr1->setTrainMethod(LogisticRegression::BATCH);lr1->setMiniBatchSize(1);//训练分类器lr1->train(data_train, ROW_SAMPLE, labels_train);Mat responses;//预测lr1->predict(data_test, responses);// 展示预测结果cout << "原始数据 vs 预测数据:" << endl;labels_test.convertTo(labels_test, CV_32S);  //转换为整型cout << labels_test.t() << endl;cout << responses.t() << endl;cout << "accuracy: " << calculateAccuracyPercent(labels_test, responses) << "%" << endl;waitKey(0);return 0;
}