最近公司将matlab中的算法要搬到java中来展示，本篇将向你展示如何不去调用matlab，纯用java来计算T检验。此代码算出结果与matlab、excel、的计算逻辑相同，自然结果也相同。 在编写此代码之前，我找过在线计算的网站，发现于matlab的计算结果不同，且差距较大，应该是计算逻辑不同。
前提需要引入maven依赖，apach的math3公共计算包，包括各种各样的计算
<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-math3 --> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-math3</artifactId> <version>3.6.1</version> </dependency>以下为代码片段：
package success; import org.apache.commons.math3.distribution.TDistribution; import org.apache.commons.math3.stat.descriptive.moment.StandardDeviation; public class TtestDemo { public static void main(String[] args) { double[] x= {119, 114, 126, 98, 75, 93, 125, 103, 91, 98, 90, 108, 91, 122, 110, 103, 148, 81, 83, 113, 86, 120, 81, 102, 86, 80, 107, 87, 93, 91}; double[] y= {130, 148, 156, 126, 110, 120, 151, 135, 111, 112, 140, 143, 120, 143, 138, 129, 173, 122, 100, 158, 117, 140, 107, 130, 129, 109, 139, 108, 125, 129}; TtestDemo t = new TtestDemo(); double t1 = t.getT(x, y); System.out.println(t1); double p = t.getP(x, y); System.out.println(p); } /** * 拿到T值 * @param x * @param y * @return */ public double getT(double x[],double y[]){ double a = getMean(x)-getMean(y); double b = getStandardDeviation(x,y); double c = Math.sqrt(x.length); double v = a / (b /c); return v; } /** * 计算列平均 * @param array * @return */ public double getMean(double[] array) { int n=array.length; double sum=0; for (double d : array) { sum=sum+d; } return sum/n; } /** * 计算标准偏差 * @param x * @param y * @return */ public double getStandardDeviation (double[] x,double[] y){ double[] z =new double[x.length]; for(int i=0;i<x.length;i++){ z[i]=x[i]-y[i]; } StandardDeviation standardDeviation =new StandardDeviation(); double evaluate = standardDeviation.evaluate(z); return evaluate; } /** * 得到P值 * @param x * @param y * @return */ public double getP(double [] x, double [] y) { int free = x.length-1; double t= getT(x, y); TDistribution td=new TDistribution(free); double cumulative = td.cumulativeProbability(t); double p; if(t>0) { p=(1-cumulative)*2; }else { p=cumulative*2; } return p; } }