java实现f检验

骑猪看日落 2023-06-27 03:14 36阅读 0赞

### 文章目录 ###

*   *  场景
     *  maven
     *  用法
     *  代码

## 场景 ##

用于两个总体方差之间的比较。

## maven ##

<dependencies>
    		
    		<dependency>
    			<groupId>net.sf.jsci</groupId>
    			<artifactId>jsci</artifactId>
    			<version>1.2</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.apache.commons</groupId>
    			<artifactId>commons-math3</artifactId>
    			<version>3.6.1</version>
    		</dependency>
    
    	</dependencies>

## 用法 ##

public class FtestDemo {
    
    	/**
    	 * two-sided test
    	 * @param args
    	 */
    	public static void main(String[] args) {
    		double[] x= {300,280,344,385,372,360,288,321,376,290,301,283};
    		double[] y= {274,220,308,336,198,300,315,258,318,310,332,263};
    		Ftest f=new Ftest(x, y);
    		System.out.println(f.getPValue());
    
    	}
    
    }

## 代码 ##

package com.math.statistics;
    
    import org.apache.commons.math3.stat.descriptive.moment.Variance;
    
    import JSci.maths.statistics.FDistribution;
    
    public class Ftest {
    	private double[] x;
    
    	private double[] y;
    
    	Variance variance = new Variance();
    
    	public Ftest(double[] x, double[] y) {
    		super();
    		this.x = x;
    		this.y = y;
    	}
    
    	public double[] getX() {
    		return x;
    	}
    
    	public void setX(double[] x) {
    		this.x = x;
    	}
    
    	public double[] getY() {
    		return y;
    	}
    
    	public void setY(double[] y) {
    		this.y = y;
    	}
    
    	public double getXDegreesOfFreedom() {
    		return x.length - 1;
    	}
    
    	public double getYDegreesOfFreedom() {
    		return y.length - 1;
    	}
    
    	public double getXVariance() {
    
    		return variance.evaluate(x);
    	}
    
    	public double getYVariance() {
    
    		return variance.evaluate(y);
    	}
    
    	public double getPValue() {
    		double q=getXVariance()*getXVariance();
    		double p=getYVariance()*getYVariance();
    		double f=q/p;
    		FDistribution fd=new FDistribution(x.length - 1, y.length - 1);
    		double cumulative = fd.cumulative(f);
    		return (1-cumulative)*2;
    	}
    }