本文是實驗設計與分析(第6版,Montgomery著,傅玨生譯) 第3章單因子實驗:方差分析3.11思考題3.7 R語言解題。主要涉及單因子方差分析,正態性假設檢驗,殘差與擬合值的關系圖,平方根變換。
X<-c(3,5,3,7,6,5,3,2,1,6,1,3,4,7,5,6,3,2,1,7,4,1,3,5,7,1,2,4,2,7,3,5,7,5,10,3,4,7,2,7)
A<-factor(rep(1:4,each=10))
miscellany<-data.frame(X,A)
aov.mis<-aov(X~A, data=miscellany)
summary(aov.mis)
> summary(aov.mis)???????????
Df Sum Sq Mean Sq F value Pr(>F)
A??????????? 3? 16.67?? 5.558??? 1.11? 0.358
Residuals?? 36 180.30?? 5.008??????????????
TukeyHSD(aov.mis)
> TukeyHSD(aov.mis)?
Tukey multiple comparisons of means
??? 95% family-wise confidence level
Fit: aov(formula = X ~ A, data = miscellany)
$A
??? diff??????? lwr????? upr???? p adj
2-1 -0.2 -2.8954706 2.495471 0.9971215
3-1 -0.5 -3.1954706 2.195471 0.9586389
4-1? 1.2 -1.4954706 3.895471 0.6314346
3-2 -0.3 -2.9954706 2.395471 0.9904787
4-2? 1.4 -1.2954706 4.095471 0.5082612
4-3? 1.7 -0.9954706 4.395471 0.3392640
opar <- par(mfrow=c(2,2),cex=.8)
plot(aov.mis)
par(opar)
(c)
# 使用sqrt()函數進行平方根變換
sqrt_transformed_data <- sqrt(X)
print(sqrt_transformed_data)
miscellany<-data.frame(sqrt_transformed_data,A)
aov.mis<-aov(sqrt_transformed_data ~A, data=miscellany)
summary(aov.mis)
> summary(aov.mis)
??????????? Df Sum Sq Mean Sq F value Pr(>F)
A??????????? 3? 1.087 ??0.3622?? 1.105?? 0.36
Residuals?? ??36 ?11.807? 0.3280?????