Change position of specific string in a string vector in R using Slice or Stringr?-CodePudding

This is my vector

my_vec <- letters

Is it possible to put z letter on 3rd position using slice (dplyr) or maybe stringr ?

Its a simple permutation.

CodePudding user response：

You can build a permutation function yourself:

permute <- function(x, i, j) {
  x[c(i, j)] <- x[c(j, i)]
  x} 

permute(letters, 26, 3)
[1] "a" "b" "z" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u"
[22] "v" "w" "x" "y" "c"

CodePudding user response：

We can use indexing in base R

my_vec[c(1:2, length(my_vec), 4:length(my_vec)-1)]

CodePudding user response：

For easier control, you can define some vectors that store the information for your transformation.

target_char <- "z"
target_pos <- 3

my_vec <- letters

append(my_vec[my_vec != target_char], target_char, target_pos - 1)

Which is essentially this:

append(my_vec[my_vec != "z"], "z", 2)

Output

 [1] "a" "b" "z" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p"
[18] "q" "r" "s" "t" "u" "v" "w" "x" "y"

CodePudding user response：

You could do

letters %>% 
  as_tibble() %>% 
  slice(1:2, 26,3:25) %>%   
  pull()