C++単刷《机械学习実戦》——kNNアルゴリズム完全コード 6203 ワード パターン認識 マシン学習 #include #include #include #include #include #include #include #include using namespace std; double group[4][2] = { { 1.0, 1.1 }, { 1.0, 1.0 }, { 0, 0 }, { 0, 0.1 } }; string labels[4] = { "A", "A", "B", "B" }; struct man { double fly; double game; double icecream; string eval; }; void sort(double* data, int n, int k) // , k //data: ,n: ,k: k { int temp; for (int i = 0; i < k; i++) { for (int j = i+1; j < n; j++) { if (*(data + i) > *(data + j)) { temp = *(data + i); *(data + i) = *(data + j); *(data + j) = temp; } } } } void sortIndex(double* data, int* sorted_index2, int n) // , //data: ,sorted_index2: ,n: { int index = 0; int* sorted_index = new int[n]; for (int i = 0; i < n; i++) { index = 0; for (int j = 0; j < n; j++) { if (data[i] > data[j]) index++; else if (data[i] == data[j] && i > j) index++; } sorted_index[i] = index; } for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (i == sorted_index[j]) sorted_index2[i] = j; } } delete sorted_index; } vector readFile(const char* file_name) // { string data_str; vector data_list; fstream file; file.open(file_name,ios::in); if (file.is_open()) { while (getline(file, data_str)) { man data; istringstream record(data_str); record >> data.fly; record >> data.game; record >> data.icecream; record >> data.eval; data_list.push_back(data); } } return data_list; } void data2matrix(vector data_list, double* dataSet, string labels[], double& length_fly, double& length_game, double& length_icecream) // , //data_list: ,dataSet: ,labels: ,length_fly....: { int index = 0; auto it = data_list.begin(); double min_fly = it->fly; double max_fly = it->fly; double min_game = it->game; double max_game = it->game; double min_icecream = it->icecream; double max_icecream = it->icecream; for (; it != data_list.end(); ++it) { if (min_fly > it->fly) min_fly = it->fly; if (max_fly < it->fly) max_fly = it->fly; if (min_game > it->game) min_game = it->game; if (max_game < it->game) max_game = it->game; if (min_icecream > it->icecream) min_icecream = it->icecream; if (max_icecream < it->icecream) max_icecream = it->icecream; } length_fly = max_fly - min_fly; length_game = max_game - min_game; length_icecream = max_icecream - min_icecream; for (auto it = data_list.begin(); it != data_list.end(); ++it) { *(dataSet + index * 3) = it->fly / length_fly; *(dataSet + index * 3 + 1) = it->game / length_game; *(dataSet + index * 3 + 2) = it->icecream / length_icecream; labels[index] = it->eval; ++index; } } void data2matrix2(man person, double* data,double length_fly, double length_game, double length_icecream) { data[0] = person.fly / length_fly; data[1] = person.game / length_game; data[2] = person.icecream / length_icecream; } string classify(double* inX,double* dataSet,string labels[],int k,int size,int dataSetSize) //kNN //inX: ,dataSet: ,labels: ,k:k ,size: ,dataSetSize: { double sum = 0; double* diff_array = new double[size]; double* diff_all = new double[dataSetSize]; int* sorted_index = new int[dataSetSize]; string label; map label_count; for (int i = 0; i < dataSetSize; i++) // , diff_array { sum = 0; for (int j = 0; j < size; j++) { diff_array[j] = *(inX + j) - *(dataSet + i*size + j); sum += (diff_array[j] * diff_array[j]); } diff_all[i] = sqrt(sum); } // , sortIndex(diff_all, sorted_index, dataSetSize); for (int i = 0; i < k; i++) // k , label_count { label = labels[sorted_index[i]]; ++label_count[label]; } // , auto map_it = label_count.begin(); label = map_it->first; int max_count = map_it->second; for (; map_it != label_count.end(); map_it++) { if (max_count < map_it->second) { max_count = map_it->second; label = map_it->first; } } delete diff_array; delete diff_all; delete sorted_index; return label; } int main() { /*string result; string line; double point[2]; cout << "please input the coodinate of the pixel" << endl; while (getline(cin, line)) { istringstream record(line); record >> point[0]; record >> point[1]; result = classify(point, &group[0][0], labels, 3, 2, 4); cout << "the result is: " << result << endl; cout << "please input the coodinate of the pixel" << endl; }*/ vector data_list; data_list = readFile("datingTestSet.txt"); int size = 3; int dataSetSize = data_list.size(); double* dataSet = new double[dataSetSize*3]; string* labels = new string[dataSetSize]; double length_fly = 0; double length_game = 0; double length_icecream = 0; data2matrix(data_list, dataSet, labels, length_fly, length_game, length_icecream); // ,ratio double ratio = 0.1; string result; int error_count = 0; int num_test = dataSetSize * ratio; string label; for (int i = 0; i < num_test; i++) { result = classify(dataSet + i * 3, dataSet + num_test * 3, labels + num_test, 3, 3, dataSetSize - num_test); cout <> person.fly; record >> person.game; record >> person.icecream; data2matrix2(person, data, length_fly, length_game, length_icecream); result = classify(data, dataSet, labels, 3, 3, dataSetSize); person.eval = result; cout << result << endl; } delete dataSet; delete data; return 0; } type_traits Maxscale2.0からMySQL5.7に接続する