k_means算法的C++实现

#include <iostream>
#include <fstream>
#include <cmath>
#include <ctime>
using namespace std;

const int N = 10000;

typedef struct {
double x1,x2;
int flag;
}oneNode;

oneNode node
;
int k,n;

void DataInput();
void SetInitial(oneNode *p,oneNode *q);
void SetQzero(oneNode &qi);
bool GetExist(int xm,int *sb,int i);
void DataIteration(oneNode *p,oneNode *q,double &E1,double &E3);
double GetRange(oneNode &node1,oneNode &node2);
bool JudgeCondition(oneNode *p,oneNode *q);
void DataOutput(oneNode *p,double E1,double E3);

int main(){
int E2=0;
double E1 = 0,E3;
n = 0;

DataInput();                                 //将txt文件中记录读入，存储到oneNode列表中

cout<<"请输入新的聚类数目：";
cin>>k;
oneNode *p = new oneNode[k];
oneNode *q = new oneNode[k];

SetInitial(p,q);                             //初始化开始的k个聚类中心

DataIteration(p,q,E1,E3);                    //循环处理每条记录，获得新的聚类中心

DataOutput(p,E1,E3);                         //输出程序运行结果

delete[] q;
delete[] p;
return 0;
}

void DataInput(){
ifstream ifs;                                //通过txt文件，读入所有记录,将记录存储到oneNode列表中
ifs.open("D:\k_means\\aa11.txt");
if (!ifs.is_open())
{
cout<<"文件读取失败"<<endl;
exit(0);
}

while (!ifs.eof())                           //将txt文件中记录，存储到node[]中
{
ifs>>node
.x1;
ifs>>node
.x2;
n++;
}
}

void SetInitial(oneNode *p,oneNode *q){
int xm;
int *sb = new int[k];
srand((unsigned)time(0));
for (int i = 0;i < k;i++)
{
do
{
xm = rand()%n;
} while (GetExist(xm,sb,i));
sb[i] = xm;

p[i] = node[xm];

SetQzero(q[i]);
}
delete[] sb;
}

void SetQzero(oneNode &qi){
qi.x1 = 0;
qi.x2 = 0;
qi.flag = 0;
}

bool GetExist(int xm,int *sb,int i){
bool b = false;
for (int j = 0;j < i;j++)
{
if (sb[j] == xm)
{
b = true;
break;
}
}
return b;
}

void DataIteration(oneNode *p,oneNode *q,double &E1,double &E3){
int i,j,E2 = 0;
bool b;
do
{
E3 = 0;
for(i = 0;i < n;i++){
double mm = GetRange(node[i],p[0]);
int m = 0;
for (j = 1;j < k;j++)
{
double nn = GetRange(node[i],p[j]);
if (mm > nn)
{
mm = nn;
m = j;
}
}
node[i].flag = m;
E3 +=  GetRange(node[i],p[m]);
q[m].x1 += node[i].x1;
q[m].x2 += node[i].x2;
q[m].flag += 1;
}
if (E2 == 0)
{
E1 = E3;
}else if(E2 > 0){
if (E1 <= E3)
{
break;
}else{
E1 = E3;
}
}
E2++;
for (i = 0;i < k;i++)
{
if (q[i].flag != 0)
{
q[i].x1 = q[i].x1/q[i].flag;
q[i].x2 = q[i].x2/q[i].flag;
}
}
b = JudgeCondition(p,q);
for (i = 0;i < k;i++)
{
p[i] = q[i];

SetQzero(q[i]);
}
} while (b);

}

double GetRange(oneNode &node1,oneNode &node2){
return pow(node1.x1-node2.x1,2)+pow(node1.x2-node2.x2,2);
}

bool JudgeCondition(oneNode *p,oneNode *q){
bool bo = false;
for (int i = 0;i < k;i++)
{
if (pow(p[i].x1-q[i].x1,2)+pow(p[i].x2-q[i].x2,2) >= 5.0)
{
bo = true;
break;
}

}
return bo;
}

void DataOutput(oneNode *p,double E1,double E3){
if (E1 != E3){
cout<<"操作失败"<<endl;
}else{
cout<<"本次总体误差是："<<E1<<endl;
ofstream ofile("D://k_means/aa11result.txt");
for (int i = 0;i < k;i++)
{
ofile<<"第"<<i+1<<"个聚类中心是："<<"("<<p[i].x1<<","<<p[i].x2<<")"<<endl<<"属于第"<<i+1<<"个聚类的所有点是："<<endl;
for (int j = 0;j < n;j++)
{
if (node[j].flag == i)
{
ofile<<node[j].x1<<" "<<node[j].x2<<endl;
}
}
}

}
}