3  多因素方差分析

3.1 2 x 2 两因素析因设计资料的方差分析

使用课本例11-1的数据,自己手动摘录:

df11_1 <- data.frame(
  x1 = rep(c("外膜缝合","束膜缝合"), each = 10),
  x2 = rep(c("缝合1个月","缝合2个月"), each = 5),
  y = c(10,10,40,50,10,30,30,70,60,30,10,20,30,50,30,50,50,70,60,30)
)

str(df11_1)
## 'data.frame':    20 obs. of  3 variables:
##  $ x1: chr  "外膜缝合" "外膜缝合" "外膜缝合" "外膜缝合" ...
##  $ x2: chr  "缝合1个月" "缝合1个月" "缝合1个月" "缝合1个月" ...
##  $ y : num  10 10 40 50 10 30 30 70 60 30 ...

数据一共3列,第1列是缝合方法,第2列是时间,第3列是轴突通过率。

进行析因设计资料的方差分析:

f1 <- aov(y ~ x1 * x2, data = df11_1)

summary(f1)
##             Df Sum Sq Mean Sq F value Pr(>F)  
## x1           1    180     180   0.600 0.4499  
## x2           1   2420    2420   8.067 0.0118 *
## x1:x2        1     20      20   0.067 0.7995  
## Residuals   16   4800     300                 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

结果显示了A因素主效应、B因素主效应、AB交互作用的自由度、离均差平方和、均方误差、F值、P值等,可以看到结果和课本是一致的!

简单介绍一下可视化两因素析因设计的方法:

interaction.plot(df11_1$x2, df11_1$x1, df11_1$y, type = "b", 
                 col = c("red","blue"), pch = c(12,15),
                 xlab = "缝合时间", ylab = "轴突通过率")

另外一种可视化方法:

library(gplots)
## 
## Attaching package: 'gplots'
## The following object is masked from 'package:stats':
## 
##     lowess

attach(df11_1)

plotmeans(y ~ interaction(x1,x2),
          connect = list(c(1,3), c(2,4)),
          col = c("red","darkgreen"),
          main = "两因素析因设计",
          xlab = "时间和方法的交互")

再介绍一种方法:

library(HH)
## Loading required package: lattice
## Loading required package: grid
## Loading required package: latticeExtra
## Loading required package: multcomp
## Loading required package: mvtnorm
## Loading required package: survival
## Loading required package: TH.data
## Loading required package: MASS
## 
## Attaching package: 'TH.data'
## The following object is masked from 'package:MASS':
## 
##     geyser
## Loading required package: gridExtra
## 
## Attaching package: 'HH'
## The following object is masked from 'package:gplots':
## 
##     residplot

interaction2wt(y ~ x1 * x2)

detach(df11_1)

3.2 I x J 两因素析因设计资料的方差分析

使用课本例11-2的数据,自己手动摘录:

df11_2 <- data.frame(
  druga = rep(c("1mg","2.5mg","5mg"), each = 3),
  drugb = rep(c("5微克","15微克","30微克"),each = 9),
  y = c(105,80,65,75,115,80,85,120,125,115,105,80,125,130,90,65,
        120,100,75,95,85,135,120,150,180,190,160)
)

str(df11_2)
## 'data.frame':    27 obs. of  3 variables:
##  $ druga: chr  "1mg" "1mg" "1mg" "2.5mg" ...
##  $ drugb: chr  "5微克" "5微克" "5微克" "5微克" ...
##  $ y    : num  105 80 65 75 115 80 85 120 125 115 ...

数据一共3列,第1列是a药物的剂量(3种剂量,代表3个水平),第2列是b药物的剂量(3种剂量),第3列是镇痛时间。

进行两因素三水平的析因设计资料方差分析:

f2 <- aov(y ~ druga * drugb, data = df11_2)

summary(f2)
##             Df Sum Sq Mean Sq F value  Pr(>F)   
## druga        2   6572    3286   8.470 0.00256 **
## drugb        2   7022    3511   9.050 0.00190 **
## druga:drugb  4   7872    1968   5.073 0.00647 **
## Residuals   18   6983     388                   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

结果和课本也是一模一样的哦!

3.3 I x J x K 三因素析因设计资料的方差分析

使用课本例11-3的数据,

df11_3 <- foreign::read.spss("datasets/例11-03-5种军装热感觉5-2-2.sav", 
                             to.data.frame = T,reencode="UTF-8")
## re-encoding from UTF-8

df11_3$a <- factor(df11_3$a)

str(df11_3)
## 'data.frame':    100 obs. of  4 variables:
##  $ b: Factor w/ 2 levels "干燥","潮湿": 1 1 1 1 1 1 1 1 1 1 ...
##  $ c: Factor w/ 2 levels "静坐","活动": 1 1 1 1 1 1 1 1 1 1 ...
##  $ a: Factor w/ 5 levels "1","2","3","4",..: 1 1 1 1 1 2 2 2 2 2 ...
##  $ x: num  0.25 -0.25 1.25 -0.75 0.4 ...
##  - attr(*, "variable.labels")= Named chr [1:4] "活动环境" "活动状态" "军装类型" "主观热感觉"
##   ..- attr(*, "names")= chr [1:4] "b" "c" "a" "x"
##  - attr(*, "codepage")= int 65001

进行3因素吸引设计资料的方差分析:

f3 <- aov(x ~ b * c * a, data = df11_3)

summary(f3)
##             Df Sum Sq Mean Sq F value   Pr(>F)    
## b            1   9.94    9.94  23.138 6.98e-06 ***
## c            1 283.35  283.35 659.485  < 2e-16 ***
## a            4   5.20    1.30   3.024   0.0224 *  
## b:c          1  12.68   12.68  29.514 5.82e-07 ***
## b:a          4   1.94    0.48   1.128   0.3491    
## c:a          4   1.48    0.37   0.862   0.4905    
## b:c:a        4   1.61    0.40   0.937   0.4472    
## Residuals   80  34.37    0.43                     
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

结果也是和课本一模一样。

3.4 正交设计资料的方差分析

使用课本例11-4的数据

df11_4 <- data.frame(
  a = rep(c("5度","25度"),each = 4),
  b = rep(c(0.5, 5.0), each = 2),
  c = c(10, 30),
  d = c(6.0, 8.0,8.0,6.0,8.0,6.0,6.0,8.0),
  x = c(86,95,91,94,91,96,83,88)
)

df11_4$a <- factor(df11_4$a)
df11_4$b <- factor(df11_4$b)
df11_4$c <- factor(df11_4$c)
df11_4$d <- factor(df11_4$d)

str(df11_4)
## 'data.frame':    8 obs. of  5 variables:
##  $ a: Factor w/ 2 levels "25度","5度": 2 2 2 2 1 1 1 1
##  $ b: Factor w/ 2 levels "0.5","5": 1 1 2 2 1 1 2 2
##  $ c: Factor w/ 2 levels "10","30": 1 2 1 2 1 2 1 2
##  $ d: Factor w/ 2 levels "6","8": 1 2 2 1 2 1 1 2
##  $ x: num  86 95 91 94 91 96 83 88

进行正交设计资料的方差分析:

f4 <- aov(x ~ a + b + c + d + a*b, data = df11_4)

summary(f4)
##             Df Sum Sq Mean Sq F value Pr(>F)  
## a            1    8.0     8.0     3.2 0.2155  
## b            1   18.0    18.0     7.2 0.1153  
## c            1   60.5    60.5    24.2 0.0389 *
## d            1    4.5     4.5     1.8 0.3118  
## a:b          1   50.0    50.0    20.0 0.0465 *
## Residuals    2    5.0     2.5                 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

结果和课本一模一样,用R语言进行方差分析真是太简单了!!!!

3.5 嵌套设计资料的方差分析

使用课本例11-6的数据。

df <- data.frame(factor1 = factor(rep(c("A","B","C"),each=6)),
                 factor2 = factor(rep(c(70,80,90,55,65,75,90,95,100),each=2)),
                 y = c(82,84,91,88,85,83,65,61,62,59,56,60,71,67,75,78,85,89)
                 )
str(df)
## 'data.frame':    18 obs. of  3 variables:
##  $ factor1: Factor w/ 3 levels "A","B","C": 1 1 1 1 1 1 2 2 2 2 ...
##  $ factor2: Factor w/ 8 levels "55","65","70",..: 3 3 5 5 6 6 1 1 2 2 ...
##  $ y      : num  82 84 91 88 85 83 65 61 62 59 ...

df
##    factor1 factor2  y
## 1        A      70 82
## 2        A      70 84
## 3        A      80 91
## 4        A      80 88
## 5        A      90 85
## 6        A      90 83
## 7        B      55 65
## 8        B      55 61
## 9        B      65 62
## 10       B      65 59
## 11       B      75 56
## 12       B      75 60
## 13       C      90 71
## 14       C      90 67
## 15       C      95 75
## 16       C      95 78
## 17       C     100 85
## 18       C     100 89

factor1是一级实验因素(不同的催化剂), factor2是二级实验因素(不同的温度),y是因变量。

进行嵌套实验设计的方差分析:

f <- aov(y ~ factor1/factor2, data = df)
summary(f)
##                 Df Sum Sq Mean Sq F value   Pr(>F)    
## factor1          2 1956.0   978.0  177.82 5.83e-08 ***
## factor1:factor2  6  401.0    66.8   12.15 0.000716 ***
## Residuals        9   49.5     5.5                     
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

结果和课本相同。

3.6 裂区设计资料的方差分析

使用课本例11-7的数据。这是一个完全随机的2*2裂区设计。

df <- data.frame(factorA = factor(rep(c("a1","a2"),each=10)),
                 factorB = factor(rep(c("b1","b2"),10)),
                 id = factor(rep(c(1:10),each=2)),
                 y = c(15.75,19.00,15.50,20.75,15.50,18.50,17.00,20.50,16.50,20.00,
                       18.25,22.25,18.50,21.50,19.75,23.50,21.50,24.75,20.75,23.75)
                 )
str(df)
## 'data.frame':    20 obs. of  4 variables:
##  $ factorA: Factor w/ 2 levels "a1","a2": 1 1 1 1 1 1 1 1 1 1 ...
##  $ factorB: Factor w/ 2 levels "b1","b2": 1 2 1 2 1 2 1 2 1 2 ...
##  $ id     : Factor w/ 10 levels "1","2","3","4",..: 1 1 2 2 3 3 4 4 5 5 ...
##  $ y      : num  15.8 19 15.5 20.8 15.5 ...

df
##    factorA factorB id     y
## 1       a1      b1  1 15.75
## 2       a1      b2  1 19.00
## 3       a1      b1  2 15.50
## 4       a1      b2  2 20.75
## 5       a1      b1  3 15.50
## 6       a1      b2  3 18.50
## 7       a1      b1  4 17.00
## 8       a1      b2  4 20.50
## 9       a1      b1  5 16.50
## 10      a1      b2  5 20.00
## 11      a2      b1  6 18.25
## 12      a2      b2  6 22.25
## 13      a2      b1  7 18.50
## 14      a2      b2  7 21.50
## 15      a2      b1  8 19.75
## 16      a2      b2  8 23.50
## 17      a2      b1  9 21.50
## 18      a2      b2  9 24.75
## 19      a2      b1 10 20.75
## 20      a2      b2 10 23.75

进行裂区设计的方差分析:

f <- aov(y ~ factorA * factorB + Error(id/factorB), data = df)
summary(f)
## 
## Error: id
##           Df Sum Sq Mean Sq F value   Pr(>F)    
## factorA    1  63.01   63.01   28.01 0.000735 ***
## Residuals  8  18.00    2.25                     
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Error: id:factorB
##                 Df Sum Sq Mean Sq F value   Pr(>F)    
## factorB          1  63.01   63.01  252.05 2.48e-07 ***
## factorA:factorB  1   0.11    0.11    0.45    0.521    
## Residuals        8   2.00    0.25                     
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

结果同课本相同。