3.聚类–K-means的Java实现

importjava.lang.annotation.Annotation;
importjava.lang.reflect.Field;
importjava.lang.reflect.Method;
importjava.util.ArrayList;
importjava.util.List;

/**
*
*@author阿飞哥
*
*/
publicclassKmeans<T>{

/**
*所有数据列表
*/
privateList<T>players=newArrayList<T>();

/**
*数据类别
*/
privateClass<T>classT;

/**
*初始化列表
*/
privateList<T>initPlayers;

/**
*需要纳入kmeans算法的属性名称
*/
privateList<String>fieldNames=newArrayList<String>();

/**
*分类数
*/
privateintk=1;

publicKmeans(){

}

/**
*初始化列表
*
*@paramlist
*@paramk
*/
publicKmeans(List<T>list,intk){
this.players=list;
this.k=k;
Tt=list.get(0);
this.classT=(Class<T>)t.getClass();
Field[]fields=this.classT.getDeclaredFields();
System.out.println("fields---------------------------------------------="+fields.length);
for(inti=0;i<fields.length;i++){
AnnotationkmeansAnnotation=fields[i]
.getAnnotation(KmeanField.class);
if(kmeansAnnotation!=null){
fieldNames.add(fields[i].getName());
System.out.println("fieldNames.add"+fields[i].getName());

}

}

initPlayers=newArrayList<T>();
for(inti=0;i<k;i++){
initPlayers.add(players.get(i));
}
}

publicList<T>[]comput(){
List<T>[]results=newArrayList[k];

booleancenterchange=true;
while(centerchange){
centerchange=false;
for(inti=0;i<k;i++){
results[i]=newArrayList<T>();
}
for(inti=0;i<players.size();i++){
Tp=players.get(i);
double[]dists=newdouble[k];
for(intj=0;j<initPlayers.size();j++){
TinitP=initPlayers.get(j);
/*计算距离*/
doubledist=distance(initP,p);
//doubledist=1.0;
//doubledist=LevenshteinDistance.levenshteinDistance(initP,p);
//System.out.println("dist="+dist);

dists[j]=dist;
}

intdist_index=computOrder(dists);
//System.out.println("dist_index="+dist_index);
results[dist_index].add(p);
}

//System.out.println("results[0].size()="+results[0].size());

for(inti=0;i<k;i++){//在每一个簇中寻找中心点
Tplayer_new=findNewCenter(results[i]);
//System.out.println("results[i]"+i+"----"+k+"---===="+results[i].size()+"===="+player_new.toString());
Tplayer_old=initPlayers.get(i);
if(!IsPlayerEqual(player_new,player_old)){
centerchange=true;
initPlayers.set(i,player_new);
}
}
}
//System.out.println("results+"+results.length);
returnresults;
}

/**
*比较是否两个对象是否属性一致
*
*@paramp1
*@paramp2
*@return
*/
publicbooleanIsPlayerEqual(Tp1,Tp2){
if(p1==p2){
returntrue;
}
if(p1==null||p2==null){
returnfalse;
}

booleanflag=true;
try{
for(inti=0;i<fieldNames.size();i++){

StringfieldName=fieldNames.get(i);
StringgetName="get"
+fieldName.substring(0,1).toUpperCase()
+fieldName.substring(1);
//System.out.println(fieldNames);
Objectvalue1=invokeMethod(p1,getName,null);
Objectvalue2=invokeMethod(p2,getName,null);
if(!value1.equals(value2)){
flag=false;
break;
}
}
}catch(Exceptione){
e.printStackTrace();
flag=false;
}

returnflag;
}

/**
*得到新聚类中心对象
*
*@paramps
*@return
*/
publicTfindNewCenter(List<T>ps){
try{
Tt=classT.newInstance();
if(ps==null||ps.size()==0){
returnt;
}

double[]ds=newdouble[fieldNames.size()];
for(Tvo:ps){
for(inti=0;i<fieldNames.size();i++){
StringfieldName=fieldNames.get(i);
StringgetName="get"
+fieldName.substring(0,1).toUpperCase()
+fieldName.substring(1);
Objectobj=invokeMethod(vo,getName,null);
Doublefv=(obj==null?0:Double.parseDouble(obj+""));
ds[i]+=fv;
}

}

//System.out.println("-----------------");
for(inti=0;i<fieldNames.size();i++){
ds[i]=ds[i]/ps.size();//平均距离
StringfieldName=fieldNames.get(i);

/*给对象设值*/
StringsetName="set"
+fieldName.substring(0,1).toUpperCase()
+fieldName.substring(1);

//invokeMethod(t,setName,newClass[]{double.class},ds[i]);
System.out.println("ds[i]++="+ds[i]+"----ps.size()"+ps.size());
invokeMethod(t,setName,newClass[]{double.class},ds[i]);

}

returnt;
}catch(Exceptionex){
ex.printStackTrace();
}
returnnull;

}

/**
*得到最短距离，并返回最短距离索引
*
*@paramdists
*@return
*/
publicintcomputOrder(double[]dists){
doublemin=0;
intindex=0;
for(inti=0;i<dists.length-1;i++){
doubledist0=dists[i];
if(i==0){
min=dist0;
index=0;
}
doubledist1=dists[i+1];
if(min>dist1){
min=dist1;
index=i+1;
}
}

returnindex;
}

/**
*计算距离（相似性）采用欧几里得算法
*
*@paramp0
*@paramp1
*@return
*/
publicdoubledistance(Tp0,Tp1){
doubledis=0;
try{

for(inti=0;i<fieldNames.size();i++){
StringfieldName=fieldNames.get(i);
StringgetName="get"
+fieldName.substring(0,1).toUpperCase()
+fieldName.substring(1);

//System.out.println("fieldNames-----="+fieldNames.size());
Doublefield0Value=Double.parseDouble(invokeMethod(p0,getName,null)+"");
Doublefield1Value=Double.parseDouble(invokeMethod(p1,getName,null)+"");
//System.out.println("field0Value="+field0Value);
dis+=Math.pow(field0Value-field1Value,2);

}

}catch(Exceptionex){
ex.printStackTrace();
}
returnMath.sqrt(dis);

}

/*------公共方法-----*/
publicObjectinvokeMethod(Objectowner,StringmethodName,Class[]argsClass,
Object...args){
ClassownerClass=owner.getClass();

try{
Methodmethod=ownerClass.getDeclaredMethod(methodName,argsClass);

returnmethod.invoke(owner,args);
}catch(SecurityExceptione){
e.printStackTrace();
}catch(NoSuchMethodExceptione){
e.printStackTrace();
}catch(Exceptionex){
ex.printStackTrace();
}

returnnull;
}

}