rJava : プログラミング(12) T-Test

対象者の評価の前後の期間をグループとし、http://mizunolab.sist.ac.jp/2016/01/rjava-10-f-test.htmlで等分散性が得られたとし、２つのグループの違いをt.testで確かめる。

$ vi JRITest15.java
$ javac JRITest15.java
$ java -Djava.library.path=/usr/lib64/R/library/rJava/jri/ JRITest15

[VECTOR ([REAL* (-3.842989125314249)], [REAL* (42.0)], [REAL* (4.0495738809968483E-4)], [REAL* (-6.5858030454480865, -2.0505605909155538)], [REAL* (40.22727272727273, 44.54545454545455)], [REAL* (0.0)], [STRING "two.sided"], [STRING " Two Sample t-test"], [STRING "c_group1 and c_group2"])]

この場合, p-value = 4.0495738809968483E-4 となり帰無仮説が棄却。2つの期間グループに差があることがわかる。

今回利用するSQL文
SELECT * FROM operations WHERE category = 0 and operator =6

public class JRITest15 {

        public static void main(String[] args)
        {
                MySQL mysql = new MySQL();
                Rengine re = new Rengine( new String[]{"--no-save"}, false, null );
                ResultSet rs = mysql.selectOperations();

                int N = 44;
                double group1 [] = new double[N/2];
                double group2 [] = new double[N/2];//**注意i:奇数の時は+1**

                int index = 0;
                try {
                        while(rs.next()){
                                if(index < (int)(N/2)){
                                        group1[index] = rs.getDouble("value");
                                }else if(index >= (int)(N/2)){
                                        group2[index-(int)(N/2)] = rs.getDouble("value");
                                }
                                index ++;
                        }
                } catch (SQLException e) {
                        e.printStackTrace();
                }

                System.out.println(Arrays.toString(group1));
                System.out.println(Arrays.toString(group2));

                StringBuffer buf1 = new StringBuffer();
                buf1.append("c_group1<-c(");
                for(int i = 0; i < group1.length; i++){
                        if(i == group1.length-1)
                                buf1.append(group1[i]+")");
                        else
                                buf1.append(group1[i]+",");
                }
                String c_group1 = buf1.toString();
                re.eval(c_group1);

                REXP x1 = re.eval("summary(c_group1)");
                System.out.println(x1);
                double [] ary1 = x1.asDoubleArray();
                for (int i = 0; i < ary1.length; i++) {
                        System.out.println(ary1[i]);
                }

                StringBuffer buf2 = new StringBuffer();
                buf2.append("c_group2<-c(");
                for(int i = 0; i < group2.length; i++){
                        if(i == group2.length-1)
                                buf2.append(group2[i]+")");
                        else
                                buf2.append(group2[i]+",");
                }
                String c_group2 = buf2.toString();
                re.eval(c_group2);

                REXP x2 = re.eval("summary(c_group2)");
                System.out.println(x2);
                double [] ary2 = x2.asDoubleArray();
                for (int i = 0; i < ary2.length; i++) {
                        System.out.println(ary2[i]);
                }

                REXP x3 = re.eval("t.test(c_group1, c_group2, var.equal=T)");
                System.out.println(x3);
                re.end();
        }
}


p