如何在data.frame中運行多個t.test？

Question

我有一個數據，

temp_data <- as.data.frame(matrix(rbinom(9*9, 1, 0.5), ncol=9, nrow =9)) 
colnames(temp_data) <- paste(rep(c("a","b","c"), each=3), rep(c(1,2,3), 3), sep = "") 

我想在data.frame的因素運行多個t.test和獲取顯示該

 factor.1 factor.2 p.value 
[1,] "a1"  "c1"  "value 1 " 
[2,] "a2"  "c2"  "value 2 " 
[3,] "a3"  "c3"  "value 3 " 
[4,] "b1"  "c1"  "value 4 " 
[5,] "b2"  "c2"  "value 5 " 
[6,] "b3"  "c3"  "value 6 " 

我怎樣才能得到這樣的輸出文件結果如何？

Answer 1

你可以這樣做：

pa <- unlist(lapply(1:3, function(i) t.test(temp_data[, i], temp_data[, i + 6])$p.value)) 
pb <- unlist(lapply(1:3, function(i) t.test(temp_data[, i + 3], temp_data[, i + 6])$p.value)) 
p <- c(pa, pb) 
p.table <- as.matrix(data.frame(factor.1 = colnames(temp_data[1:6]), 
      factor.2 = rep(colnames(temp_data[7:9]), 2), 
      p.value = p)) 
p.table 
#  factor.1 factor.2 p.value  
# [1,] "a1"  "c1"  "0.652543514" 
# [2,] "a2"  "c2"  "0.176463197" 
# [3,] "a3"  "c3"  "0.176463197" 
# [4,] "b1"  "c1"  "0.372458894" 
# [5,] "b2"  "c2"  "0.003949773" 
# [6,] "b3"  "c3"  "0.652543514"