c45java

1. 从java中调用weka中的分类函数的问题

详细咐轮乱请见：http://stackoverflow.com/questions/8112041/error-while-using-weka-api-in-java-code-class-attribute-not-set
你应桐正该在这行 Instances instances = getArffData("E:\\Book2.arff"); // 读衡档入文件
后加入一条语句： instances.setClassIndex(instances.numAttributes() - 1);
You should set class index of for your dataset before passing it into classifier. Your classifier must know which is your outcome variable.
//Rest of your code
loader.setQuery("select * from data_training"); Instances data = loader.getDataSet(); //add this line here
data.setClassIndex(instances.numAttributes() - 1);
//if Hujan is your class attribute(outcome variable)

2. java 将字符串中含有unicode 转成中文！

publicclassConvert
{
	(Stringasciicode)
	{
		String[]asciis=asciicode.split("\\u");
		StringnativeValue=asciis[0];
		try
		{
			for(inti=1;i<asciis.length;i++)
			{
				Stringcode=asciis[i];
				nativeValue+=(char)Integer.parseInt(code.substring(0,4),16);
				if(code.length()>4)
				{
					nativeValue+=code.substring(4,code.length());
				}
			}
		}
		catch(NumberFormatExceptione)
		{
			returnasciicode;
		}
		returnnativeValue;
	}

	publicstaticvoidmain(String[]args)
	{
		Stringstr=""JWHQK_JWQC":""";
		Stringresult=ascii2native(str);
		System.out.println(result);
	}
}

3. 缂栦竴涓 java 灏忕▼搴 镐ユ眰 镐ユユユユユユ

import java.io.*;

public class Test
{
public static void main(String arg[])throws IOException{
int a=0;
int b=0;
int c=0;
int d=0;
int f=0;
int n=0;
System.out.println("璇疯緭鍏ユ垚缁,鎸夊洖杞︾‘瀹,鎴愮哗杈揿叆瀹屾垚钖,杈揿叆F鎴杅镆ョ湅缁撴灉.");
for(;;n++)
{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String s=br.readLine();
if (s.equals("F")||s.equals("f")) break;
int i=Integer.parseInt(s);

if(i>100||i<0){System.out.println("杈揿叆链夐敊璇锛佽烽吨鏂拌緭鍏!");n--; }
else
if (i>=85 && i<=100) {a++;}
if (i>=70 && i<85) {b++;}
if (i>=55 && i<70) {c++;}
if (i>=45 && i<55) {d++;}
if (i>=0 && i<45) {f++;}

}
System.out.println("鍏辫緭鍏"+ n + "涓瀛︾敓镄勬垚缁" + "\n"+
"绛夌骇A镄勫︾敓链"+ a + "涓" + "\n" +
"绛夌骇B镄勫︾敓链"+ b + "涓" + "\n" +
"绛夌骇C镄勫︾敓链"+ c + "涓" + "\n" +
"绛夌骇D镄勫︾敓链"+ d + "涓" + "\n" +
"绛夌骇F镄勫︾敓链"+ f + "涓");}
}