没有“分隔符”时，将R中的一列拆分为多列

Question

Suppose I have a data frame with eight digit numbers, each corresponding to one

x <- data.frame(y = c(12345678, 87654321))

I want 8 columns such that each column corresponds to one number ie

   y1   y2   y3   y4   y5   y6   y7   y8
    1    2    3    4    5    6    7    8     
    8    7    6    5    4    3    2    1   

(The columns don't have to be named y1 to y8, I'm just naming them that way for illustrative purposes)

Normally in R, I would use separate , but here there is no clear separator. How can I do this?

Answer 1

separate can accept column positions in the sep argument. This acts as if there were separators after columns 1, 2, ..., 7.

library(tidyr)

separate(x, y, into = paste0("y", 1:8), sep = 1:7)

giving:

  y1 y2 y3 y4 y5 y6 y7 y8
1  1  2  3  4  5  6  7  8
2  8  7  6  5  4  3  2  1

Answer 2

Here is a base R option using strsplit

as.data.frame(t(apply(x, 1, function(x) unlist(strsplit(as.character(x), "")))))
#  V1 V2 V3 V4 V5 V6 V7 V8
#1  1  2  3  4  5  6  7  8
#2  8  7  6  5  4  3  2  1

Or a tidyverse option

library(tidyverse)
x %>%
    rowid_to_column("row") %>%
    mutate(y = strsplit(as.character(y), "")) %>%
    unnest() %>%
    group_by(row) %>%
    mutate(var = paste0("y", 1:n())) %>%
    spread(var, y) %>%
    ungroup() %>%
    select(-row)
#  y1    y2    y3    y4    y5    y6    y7    y8
#  <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr>
#1 1     2     3     4     5     6     7     8
#2 8     7     6     5     4     3     2     1

Answer 3

Another R base alternative

> data.frame(do.call(rbind, strsplit(as.character(x$y), "")))
  X1 X2 X3 X4 X5 X6 X7 X8
1  1  2  3  4  5  6  7  8
2  8  7  6  5  4  3  2  1

Answer 4

Solution from stringr

data.frame(stringr::str_split_fixed(x$y, "", 8))
  X1 X2 X3 X4 X5 X6 X7 X8
1  1  2  3  4  5  6  7  8
2  8  7  6  5  4  3  2  1