r - 如何在 R 中获取多个 Stuart-Maxwell 检验的 p 值矩阵？问

Question

我有一个数据集，其中包含 1o 个问题 (Q1-Q10)。我想提取成对 Stuart-Maxwell 检验的 P 值，并将它们打印在带有列名称标题的矩阵中，这样我就可以检测哪个 P 值指的是哪个成对比较。我从专家那里得到了如何运行测试和提取结果的帮助，我尝试制作带有标题的矩阵，但失败了。如果有人可以修改我下面的代码，我将不胜感激。

data <- data.frame(Q1=sample(1:5, 20, replace=T),
               Q2=sample(1:5, 20, replace=T),
               Q3=sample(1:5, 20, replace=T),
               Q4=sample(1:5, 20, replace=T),
               Q5=sample(1:5, 20, replace=T),
               Q6=sample(1:5, 20, replace=T),
               Q7=sample(1:5, 20, replace=T),
               Q8=sample(1:5, 20, replace=T),
               Q9=sample(1:5, 20, replace=T),
               Q10=sample(1:5, 20,replace=T) )  #fake data
Labels<- names(data)
# Matrix to store the result
enter code here
groups <- unique( Labels )
result <- matrix(NA, nc=length(groups), nr=length(groups))
colnames(result) <- rownames(result) <- groups
# Loop
for( g1 in groups ) {
for( g2 in groups ) {
result[ g1, g2 ] <- 
      sapply(labels <-combn(groups, 2, simplify = FALSE), function(i) {


    require(irr)

    xtab <- table(data[,i[1]], data[,i[2]])
    test <- try(stuart.maxwell.mh(xtab))
    ifelse(class(test) == "try-error", NA, test$p)
})



}

}

result

Answer 1

你们已经很接近了。你只是混淆了两种方法。您应该将 sapply 与 combn 或两个 for 循环 一起使用。根据您的情况并根据您想要的输出 for-loop 看起来更容易:

require(irr)
data <- data.frame(Q1=sample(1:5, 20, replace=T),
                   Q2=sample(1:5, 20, replace=T),
                   Q3=sample(1:5, 20, replace=T),
                   Q4=sample(1:5, 20, replace=T),
                   Q5=sample(1:5, 20, replace=T),
                   Q6=sample(1:5, 20, replace=T),
                   Q7=sample(1:5, 20, replace=T),
                   Q8=sample(1:5, 20, replace=T),
                   Q9=sample(1:5, 20, replace=T),
                   Q10=sample(1:5, 20,replace=T) )  #fake data

# Loop
labels<- names(data)
groups <- unique(labels)
result <- matrix(NA, nc=length(groups), nr=length(groups))
colnames(result) <- labels
rownames(result) <- labels

for( g1 in groups ) {
 for( g2 in groups ) {

  xtab <- table(data[,g1], data[,g2])
  test <- try(stuart.maxwell.mh(xtab), silent = TRUE)
  pval <- ifelse(class(test) == "try-error", NA, test$p)
  result[g1, g2] <- pval

 }
}

输出:

> result
           Q1         Q2         Q3        Q4        Q5        Q6         Q7         Q8
Q1         NA 0.05881900 0.26298902        NA 0.7790233 0.5177394 0.73754470 0.30610257
Q2  0.0588190         NA 0.58635825        NA 0.1005838 0.3678794 0.17078180 0.05626191
Q3  0.2629890 0.58635825         NA 0.3173105 0.3916252 0.2541583 0.09984288 0.07472086
Q4  0.3173105 0.36787944         NA        NA        NA        NA         NA         NA
Q5  0.7790233 0.10058381 0.39162518 0.2231302        NA 0.3114032 0.14247485 0.17708783
Q6  0.5177394 0.36787944 0.25415830        NA 0.3114032        NA 0.21636999 1.00000000
Q7  0.7375447 0.17078180 0.09984288        NA 0.1424749 0.2163700         NA 0.41099506
Q8  0.3061026 0.05626191 0.07472086 0.3173105 0.1770878 1.0000000 0.41099506         NA
Q9  0.6712714 0.53408090 0.16832466 0.3173105 0.2110881 0.2635971 0.28933534 0.31414685
Q10 0.2220359 0.38332585 0.05941603 1.0000000 0.1652989 0.2578472 0.23889094 0.08826479

#the output is truncated