How to divide a data factor into subsets in R-CodePudding

I have a factor column which looks like this

id               
2000.1.ABC0123
2010.11.BCD3652

The logic is "year" "month" and "identifier" I simply want to entangle them into two columns with the specification that I need single digit months with a "0" in front as follows.

Identifier     yearmonth    
AB0123         200001 
BCD3652        201011

I played around with "paste0" and "substra", but could not get it to work.

Any help is very much appreciated.

Thanks and best, D.

CodePudding user response：

Combination of strsplit and sprintf should give you the output you need.

x = unlist(strsplit('2000.1.ABC0123', split='\\.'))
y = as.numeric(x[1:2])
sprintf('Md', y[1], y[2])
x[3]

CodePudding user response：

In Base R:

read.table(text=df$id, sep='.', col.names = c('year', 'month', 'Identifier')) |>
  transform(yearmonth = sprintf("%dd", year, month))

  year month Identifier yearmonth
1 2000     1    ABC0123    200001
2 2010    11    BCD3652    201011

Tidyverse:

df %>%
  separate(id, c('year', 'month', 'Identifier'), convert = TRUE) %>%
  mutate(month = sprintf('d', month)) %>%
  unite('yearmonth', year, month, sep='')

yearmonth Identifier
  <chr>     <chr>     
1 200001    ABC0123   
2 201011    BCD3652

CodePudding user response：

library(data.table)
DT <- fread("id               
2000.1.ABC0123
2010.11.BCD3652 ")

DT[, c("year", "month", "Identifier") := tstrsplit(id, ".", fixed = TRUE)]
DT[, yearmonth := paste0(year, sprintf("d", as.numeric(month)))]
#                 id year month Identifier yearmonth
# 1:  2000.1.ABC0123 2000     1    ABC0123    200001
# 2: 2010.11.BCD3652 2010    11    BCD3652    201011

CodePudding user response：

Here is an example using stringr and dplyr

library(tidyverse)

df_example <- tribble(~id,
                      '2000.1.ABC0123',
                      '2010.11.BCD3652')


df_example |> 
  mutate(split_cols = str_split(id,pattern = "\\.(?![:digit:])"),
         yearmonth  = split_cols |> map_chr(pluck(1)) |>  str_remove('\\.'),
         Identifier =  split_cols |> map_chr(pluck(2))
         )
#> # A tibble: 2 x 4
#>   id              split_cols yearmonth Identifier
#>   <chr>           <list>     <chr>     <chr>     
#> 1 2000.1.ABC0123  <chr [2]>  20001     ABC0123   
#> 2 2010.11.BCD3652 <chr [2]>  201011    BCD3652

^{Created on 2021-12-02 by the reprex package (v2.0.1)}