partofh.java

商业只能中数据挖掘的决策树算法 用于数据分类

package id3;

public class PartOfH {
	public static double log2( double a ) {
		return Math.log( a ) / Math.log( 2 );
	}
	
	public static double P( int a, int b ) {
		return a * Double.parseDouble( "1.0" ) / b;
	}
	
	public static double PartResult( int a, int b ) {
		if( a == 0 ) {
			return 0;
		}
		else {
			double Pa = P( a, b );
			return -( Pa * log2(Pa) );
		}
	}
}