[R 통계분석] F test (등분산검정)

[R 통계분석] F test (등분산검정)

#1. 방법

var.test(x, y, ratio = 1,
         alternative = c("two.sided", "less", "greater"),
         conf.level = 0.95, ...)

x,y 자리에 데이터 입력.

#2. 예제

> 코드

#표본생성

set.seed(1)
group1=rnorm(50,0,1)
group2=rnorm(50,0,1)

#F test 수행
var.test(group1,group2)

> 실행결과

> var.test(group1,group2)

    F test to compare two variances

data:  group1 and group2
F = 0.73641, num df = 49, denom df = 49, p-value = 0.2876
alternative hypothesis: true ratio of variances is not equal to 1
95 percent confidence interval:
 0.4178958 1.2976955
sample estimates:
ratio of variances
         0.7364113