cmean.cpp

C-means 算法

//////////////////////////////////////////////////////////////////////////
//k-mean 聚类创建日期2006年5月22日
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <time.h>
#include <math.h>
long int posnum;
const int M=1000;
const double NUM_MAX=100000000;
const double NUM_MIN=0.00000001;
int knum;
int row;
int *numperclu;//每个簇的个数
//均值聚类数据结构
struct cluster
{
	double *data;
	int dataindex;
	struct cluster *next;
};
typedef struct cluster ccnode;
typedef ccnode *ccLink;
ccLink kcluster;
//读文件，位置矩阵
double** readdata(char* s)
{
	FILE* fp;
	if ((fp=fopen(s,"rb"))==NULL)
	{
		printf("erro! cannot open file!\n");
		exit(0);
	}
	int i,j;
	double **tpos;
	tpos= (double**)malloc(M*sizeof(double*));
	for ( i=0;i<M;i++)
		tpos[i] = (double*)malloc(M*sizeof(double));
	
	char temp[100]={0};
	char *p = NULL; double x;
	for(i=0;!feof(fp);i++)
	{
		if((fgets(temp,100,fp))==NULL)
			break;
		p = temp;
		j=0;
		while(1)
		{
			x=atof(p);  
			tpos[i][j] = x;
			j++;
			if((p=strchr(p,' '))==NULL)
				break;
			p++;
		}
	}  
	posnum = i ; row = j;
	double **pos;
	pos= (double**)malloc(posnum*sizeof(double*));
	for ( i=0;i<posnum;i++)
	{ 
		pos[i] = (double*)malloc(row*sizeof(double));
		for(j=0;j<row;j++)
			pos[i][j] = tpos[i][j];		
		free(tpos[i]);
	}
	free(tpos); 
	fclose(fp); 
	return pos;
}
void insertcluster(ccLink Head,double *key,int dataindex)
{
	ccLink pointer;
	pointer = Head;
	// Head->data[0]++;
	int i;
	while (pointer->next!=NULL)
		pointer=pointer->next;

	ccLink New;
	New = (ccLink)malloc(sizeof(ccnode));
	pointer->next=New;
	New->data=(double*)malloc(row*sizeof(double));
	for (i=0;i<row;i++)
		New->data[i]=key[i];

	New->dataindex=dataindex;
	New->next=NULL;
}
////////
double dist(double* d1,double *d2)
{
	int i;double distant=0;
	for (i=0;i<row;i++)
		distant=distant+(d1[i]-d2[i])*(d1[i]-d2[i]);
	distant=sqrt(distant);
	return distant;
}
////////
int isexit(double** temp)
{
	int i,j;double distant=0.0;
	for (i=0;i<knum;i++)
	{
		/*  for (j=0;j<row;j++)
		{
			printf("%lf ",temp[i][j]);
			printf("%lf ",kcluster[i].data[j]);
		}  
		*/
		distant=distant+ dist(temp[i],kcluster[i].data);
	}
	printf("%lf\n",distant);
	if (distant<NUM_MIN)
		return 0;
	else
		return 1;
}
 //重新计算均值并赋值
void calmean(ccLink Head)
{
	int i;
	int num=0;
	double *sum=(double*)(malloc(row*sizeof(double)));
	for (i=0;i<row;i++)
		sum[i]=0;
	ccLink pointer;
	pointer=Head->next;
	for (;pointer!=NULL;pointer=pointer->next)
	{
		for (i=0;i<row;i++)
			sum[i]=sum[i]+pointer->data[i];
		num++;
	}
	for (i=0;i<row;i++)
	{
		if (num!=0)
			sum[i]=sum[i]/num;
		else
			sum[i]=0;
		Head->data[i]=sum[i];
	}
	free(sum);
}
////////////////
double** initdata()
{  
	int i,j;
	srand((unsigned)time(NULL));
	double** pos;
	pos = readdata("pos.txt");
	numperclu = (int*)malloc(knum*sizeof(int));
	for (i=0;i<knum;i++)
		numperclu[i]=0;
	int num;
	int bestnum;
	double min=NUM_MAX;
	double distant;
	kcluster=(ccLink)malloc(knum*sizeof(ccnode));
	for (i=0;i<knum;i++)
		kcluster[i].data=(double*)malloc(row*sizeof(double));
	for (i=0;i<knum;i++)
	{
		num=rand()%posnum; 
		for (j=0;j<row;j++)
			kcluster[i].data[j]=pos[num][j];

		kcluster[i].dataindex = 0;
		kcluster[i].next=NULL;
	}
	for (i=0;i<posnum;i++)
	{
		min = NUM_MAX;
		for (j=0;j<knum;j++)
		{
			distant=dist(pos[i],kcluster[j].data);
			if (distant<min)
			{
				min=distant;
				bestnum=j;
			}
		}
		insertcluster(&kcluster[bestnum],pos[i],i);
		numperclu[bestnum]++;//簇内数目加一
	}
	for (i=0;i<knum;i++)
		calmean(&kcluster[i]);
	return pos;
} 
//删除不在同一个簇内的节点，并查入到最近的簇中
void delandinsercluster(double* data,int bestnum)
{
	int i;
	for (i=0;i<knum;i++)
	{
		ccLink pointer;
		pointer = &kcluster[i];
		ccLink back=pointer;
		pointer=pointer->next;
		for ( ;pointer!=NULL;pointer=pointer->next)
		{
			if (dist(data,pointer->data)<NUM_MIN)
			{
				if (i!=bestnum)
				{
					//查入到bestnum簇中
					insertcluster(&kcluster[bestnum],data,pointer->dataindex);
					numperclu[bestnum]++;//簇内数目加一
					//删除i簇中的节点，并查入到bestnum簇中
					back->next=pointer->next;
					free(pointer->data);
					free(pointer);
					numperclu[i]--;//簇内数目减一
				}
				break;
			}//end if
			back = pointer;
		}//end for
	}//end for
}
////////////////////
int kmeancluster(double** pos)
{  
	int i,j;
	int bestnum=0;
	double distance=0.0;
	for (i=0;i<posnum;i++)
	{
		double min=NUM_MAX;
		for (j=0;j<knum;j++)
		{
			distance=dist(pos[i],kcluster[j].data);
			if (distance<min)
			{
				min=distance;
				bestnum=j;
			}
		}
		delandinsercluster(pos[i],bestnum);
	}
	double** temp=(double**)malloc(knum*sizeof(double*));
	for (i=0;i<knum;i++)
		temp[i]=(double*)malloc(row*sizeof(double));
	for (i=0;i<knum;i++)
		for (j=0;j<row;j++)
			temp[i][j]=kcluster[i].data[j];//后面的值
	                                                          
	for (i=0;i<knum;i++)
		calmean(&kcluster[i]);
	
	int isstop = isexit(temp);
	for (i=0;i<knum;i++)
		free(temp[i]);
	free(temp);
	return isstop;    
}
/////////////////
void printcluster()
{
	ccLink pointer;
	FILE* fp;
	if ((fp=fopen("out.txt","w"))==NULL)
	{
		printf("error! can't open out file!\n");
		exit(0);
	}

	int i,j;
	for (i=0;i<knum;i++)
	{
		printf("第%d组:数目:%d节点:",i,numperclu[i]);
		fprintf(fp,"%d %d ",i,numperclu[i]);
		for (pointer=kcluster[i].next;pointer!=NULL;
				pointer=pointer->next )
		{
			printf("%d ",pointer->dataindex);
			fprintf(fp,"%d ",pointer->dataindex);
		}
		printf("\n");
		fprintf(fp,"\n");
	}
	fclose(fp);
}
////////////
void freeall()
{
	free(numperclu);
	int i;
	ccLink pointer;
	ccLink tpointer;
	for(i=0;i<knum;i++)
	{
		pointer=&kcluster[i];
		pointer=pointer->next;
		while (pointer!=NULL)
		{
			tpointer=pointer;
			pointer=pointer->next;
			free(tpointer->data);
			free(tpointer);
		}
		free(kcluster[i].data);  
	}

	free(kcluster);
}
//  main
int main()
{
	knum=3;
	int i=0;
	double **pos = initdata();
	int isstop=1;
	while (isstop)
	{
		i++;
		isstop = kmeancluster(pos);
		printf("第%d次迭代\n",i);
	}
	printcluster();
	freeall();
	return 0;
}