如何在 R 中執行二因素方差齊性檢驗?


一般來說,我們可以說方差齊性檢驗是一種對比兩個或更多變數的方差,並在它們之間存在顯著差異時找出差異型別的檢驗。對於二因素方差齊性檢驗,最常用的檢驗之一是 Levene 檢驗,它可以藉助 base R 中 car 包的 leveneTest 函式輕鬆完成。

考慮下面的資料框 −

示例

 線上演示

set.seed(151)
x1<-sample(c("C1","C2","C3"),20,replace=TRUE)
x2<-sample(c("S1","S2","S3","S4","S5"),20,replace=TRUE)
y<-rnorm(20,5,2)
df1<-data.frame(x1,x2,y)
df1

輸出

  x1 x2   y
1 C2 S2 2.255857
2 C3 S5 1.726474
3 C3 S4 4.280697
4 C2 S3 7.402230
5 C2 S3 3.708252
6 C2 S4 3.978782
7 C2 S1 3.801754
8 C3 S3 6.091206
9 C2 S3 4.017412
10 C3 S3 5.383071
11 C3 S1 3.882945
12 C1 S5 6.845399
13 C1 S1 7.307996
14 C3 S4 2.255179
15 C1 S5 7.580363
16 C2 S5 7.309804
17 C2 S4 7.891359
18 C2 S3 5.522026
19 C3 S4 8.858292
20 C1 S1 3.800228

載入 car 包並在 df1 上執行 Levene 檢驗 −

library(car) leveneTest(y~x1*x2,data=df1) 
Levene's Test for Homogeneity of Variance (center = median)
Df F value Pr(>F)
group 9 1.5987 0.2374 10

讓我們看看另一示例 −

示例

 線上演示

Age_group<-sample(c("First","Second"),20,replace=TRUE)
Ethnicity<-sample(c("Asian","NorthAmerican","Chinese","Japanese"),20,replace=TRUE)
Salary<-sample(20000:50000,20)
df2<-data.frame(Age_group,Ethnicity,Salary)
df2

輸出

Age_group Ethnicity Salary
1 Second NorthAmerican 25678
2 Second Asian 34597
3 Second Chinese 49861
4 Second Chinese 37386
5 First Japanese 38426
6 Second NorthAmerican 45889
7 Second Asian 35033
8 Second NorthAmerican 46098
9 First Japanese 34070
10 Second Japanese 33618
11 First Japanese 35760
12 Second Chinese 33376
13 Second NorthAmerican 30630
14 First Asian 23820
15 Second Asian 40899
16 First Asian 35095
17 Second Chinese 43439
18 First Japanese 35641
19 Second Asian 41754
20 Second NorthAmerican 35337

在 df2 上執行 Levene 檢驗 −

leveneTest(Salary~Age_group*Ethnicity,data=df2)
Levene's Test for Homogeneity of Variance (center = median)
Df F value Pr(>F)
group 6 0.6593 0.6835 13

更新日期: 19-10-2020

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