求助（为什么这个KNN算法时好时坏，一下可以运行，一下不可以）
问题
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头文件：
#ifndef KNN_H #define KNN_H // the number of training points训练集的点数 #define N 150 // the number of patterns #define M 3//类的个数 #define TEST_NUM 100 #define K 9 typedef struct{ double a; double b; double c; double d; int label; // the class label of the training point类标号 }TrainingPoint; typedef struct{ double value; //the distance from the test point to a training point测试点距训练集的距离 int num; }Distance; /* * return the class label of the point(x, y), k specifies the number * of neighbors selected */ //返回选择的K近邻 int knn_classify(double a, double b,double c,double d, int k); /* * find the indexs of the k nearest neighbors in the training array, * and copy the indexs into the array "index" */ //将K近邻的类标号放入数组 void find_knn(double a, double b, double c,double d,int index[], int k); /* * using the labels of the k nearest neighbors to vote * to get the most frequent label */ //投票 int vote(int index[], int k); /* * sort the distances and find the indexes of k nearest neighbors. * Here "qsort" function provided in ANSI C was used */ //qsort 算法找出K近邻 void quick_sort(Distance distance[], int n, int index[], int k); /* * the function needed in "qsort"; return 0 if dist1 == dist2; * return 1 if dist1 > dist2; else return -1 */ //qsort算法比较大小 int compare(const void * dist1, const void * dist2); void print(); #endif
KNN的实现部分：
#include "knn.h" #include <math.h> #include <stdlib.h> #include <stdio.h> extern TrainingPoint training_data [N];// extern double test_data[TEST_NUM][4]; extern int test_label[TEST_NUM];//定义类标号; //extern int K; //用knn算法获得类标号 int knn_classify(double a, double b,double c,double d, int k) { int * index; int label = 0; int i = 0; index = (int *)malloc(k * sizeof(int)); //step 1: 找出最近邻 find_knn(a, b,c,d, index, k); //step 2: 类标号投票 label = vote(index, k); free(index); return label; } //从训练集中找出最近邻坐标 void find_knn(double a, double b, double c,double d,int index[], int k) { Distance distance[N]; int i = 0; //计算欧式距离 for (i = 0; i < N; i++) { distance[i].value = sqrt((a - training_data[i].a) * (a - training_data[i].a) + (b - training_data[i].b) * (b - training_data[i].b)+(c - training_data[i].c) * (c - training_data[i].c)+(d - training_data[i].d) * (d - training_data[i].d)); distance[i].num = i; } //排序（qsort algorithm最快速） quick_sort(distance, N, index, k); } //类标号投票 int vote(int index[], int k) { int i = 0; int max = 0; int cur = 0; int labels[M]; int label = 0; for(i = 0; i < M; i++) { labels[i] = 0; } for(i = 0; i < k; i++) { label = training_data[index[i]].label; labels[label-1]++; } cur = labels[0]; for(i = 1; i < M; i++) { if(labels[i] > cur) { cur = labels[i]; max = i; } } return (max+1); } //sort the distance using quick sort algorithm //qsort排序 void quick_sort(Distance distance[], int n, int index[], int k) { int i = 0; int j = 0; int max = 0; qsort(distance, n, sizeof(Distance), compare); //get the indexes of the k shortest distances for(i = 0; i < k; i++) { index[i] = distance[i].num; } } int compare(const void * arg1, const void * arg2) { Distance* dist1; Distance* dist2; dist1 = (Distance*) arg1; dist2 = (Distance*) arg2; if(dist1->value > dist2->value) { return 1; } else { if (dist1->value < dist2->value) { return -1; } else { return 0; } } }
main.cpp主要负责文件读写#include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/timeb.h> #include <time.h> #include "knn.h" TrainingPoint training_data [N]; double test_data [TEST_NUM][4]; int test_label [TEST_NUM]; //read n training data from 'filename' to buffer //将训练数据从文件读入buffer void read_training_data(char * filename, int n); //read n test data from 'filename' to buffer //将测试数据从文件读入Buffer void read_test_data(char * filename, int n); //write n data in buffer to 'filename' //将结果从Buffer写入文件 void write_data(char * filename, int n); int main(int argc, char *argv[]) { int i = 0; printf("read training data!\n"); read_training_data("./aa.txt", N); printf("read test data!\n"); read_test_data("./ab.txt", TEST_NUM); for(i = 0; i < TEST_NUM; i++) { test_label[i] = knn_classify(test_data[i][0], test_data[i][1],test_data[i][2],test_data[i][3], K); } write_data("./test_result.txt", TEST_NUM); printf("Press ENTER to continue...\n"); getchar(); return 0; } //read training data from file void read_training_data(char * filename, int n) { FILE * fp; int i = 0; char * token; char line[100]; if((fp = fopen(filename, "r")) != NULL) { for(i = 0; i < n; i++) { fgets(line, 100, fp); token = strtok(line, ","); training_data[i].a = atof(token) ; token = strtok(NULL, ","); training_data[i].b = atof(token); token = strtok(NULL, ","); training_data[i].c = atof(token) ; token = strtok(NULL, ","); training_data[i].d = atof(token) ; token = strtok(NULL, ","); training_data[i].label = atoi(token); } fclose(fp); } } //read test data from file void read_test_data(char * filename, int n) { FILE * fp; int i = 0; char * token; char line[100]; if((fp = fopen(filename, "r")) != NULL) { for(i = 0; i < n; i++) { fgets(line, 100, fp); token = strtok(line, ","); test_data[i][0] = atof(token) ; token = strtok(NULL, ","); test_data[i][1] = atof(token); token = strtok(NULL, ","); test_data[i][2] = atof(token); token = strtok(NULL, ","); test_data[i][3] = atof(token); } fclose(fp); } } //write the classification results into a txt file void write_data(char * filename, int n) {
FILE * fp; int i = 0; if((fp = fopen(filename, "w")) != NULL) { for(i = 0; i < n; i++) { fprintf(fp, "%f\t%f\t%f\t%f\t%d\n", test_data[i][0], test_data[i][1], test_data[i][2],test_data[i][3],test_label[i]); } fclose(fp); } }
为什么会出现这样的错误，谢谢好心人的指点，不胜感激~!!
