Question

我的输入矩阵

set.seed(123)
m1 <- matrix(sample(letters, 50, replace=TRUE), 5)

在这里，我想用＆＃34; A＆＃34;，＆＃34; B＆＃34;，＆＃34; C＆＃34;，＆＃34; D＆＃34;通过遵循4字母差异的模式。即＆＃34; A＆＃34;应该替换字母＆＃34; a＆＃34;，＆＃34; e＆＃34;，＆＃34; i＆＃34;，＆＃34; m＆＃34;，＆＃34; q＆＃34;，＆＃ 34;你＆＃34;，＆＃34; y＆＃34;，＆＃34; B＆＃34;替换＆＃34; b＆＃34;，＆＃34; f＆＃34;，＆＃34; j＆＃34;，....等。

我试过

replace(m1, c("a","e","i","m","q", "u", "y"), "A")

这是不正确的。

Answer 1

这是一种使用模运算的方法：

matrix(toupper(letters)[((match(m1, letters) - 1) %% 4) + 1], ncol=ncol(m1))

#      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
# [1,] "D"  "B"  "A"  "D"  "D"  "C"  "B"  "A"  "D"  "D"  
# [2,] "A"  "B"  "D"  "C"  "C"  "C"  "D"  "D"  "C"  "C"  
# [3,] "C"  "D"  "B"  "B"  "A"  "D"  "B"  "B"  "C"  "A"  
# [4,] "C"  "C"  "C"  "A"  "B"  "D"  "A"  "A"  "B"  "C"  
# [5,] "A"  "D"  "C"  "A"  "B"  "D"  "A"  "C"  "D"  "C"

Answer 2

使用简单的for - 循环：

for(i in 1:4) m1[m1 %in% letters[seq(i,26,by=4)]] <- LETTERS[i]

> m1
 [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "D"  "B"  "A"  "D"  "D"  "C"  "B"  "A"  "D"  "D"  
[2,] "A"  "B"  "D"  "C"  "C"  "C"  "D"  "D"  "C"  "C"  
[3,] "C"  "D"  "B"  "B"  "A"  "D"  "B"  "B"  "C"  "A"  
[4,] "C"  "C"  "C"  "A"  "B"  "D"  "A"  "A"  "B"  "C"  
[5,] "A"  "D"  "C"  "A"  "B"  "D"  "A"  "C"  "D"  "C"

使用模式更改矩阵中的多个值

2 个答案: