How to split a string into substrings of a given length? [duplicate]

by

Here is one way

substring("aabbccccdd", seq(1, 9, 2), seq(2, 10, 2))
#[1] "aa" "bb" "cc" "cc" "dd"

or more generally

text <- "aabbccccdd"
substring(text, seq(1, nchar(text)-1, 2), seq(2, nchar(text), 2))
#[1] "aa" "bb" "cc" "cc" "dd"

Edit: This is much, much faster

sst <- strsplit(text, "")[[1]]
out <- paste0(sst[c(TRUE, FALSE)], sst[c(FALSE, TRUE)])

It first splits the string into characters. Then, it pastes together the even elements and the odd elements.

Timings

text <- paste(rep(paste0(letters, letters), 1000), collapse="")
g1 <- function(text) {
    substring(text, seq(1, nchar(text)-1, 2), seq(2, nchar(text), 2))
}
g2 <- function(text) {
    sst <- strsplit(text, "")[[1]]
    paste0(sst[c(TRUE, FALSE)], sst[c(FALSE, TRUE)])
}
identical(g1(text), g2(text))
#[1] TRUE
library(rbenchmark)
benchmark(g1=g1(text), g2=g2(text))
#  test replications elapsed relative user.self sys.self user.child sys.child
#1   g1          100  95.451 79.87531    95.438        0          0         0
#2   g2          100   1.195  1.00000     1.196        0          0         0

More Related Contents:

  1. Split comma-separated strings in a column into separate rows
  2. Split data frame string column into multiple columns
  3. Convert string to a variable name
  4. Is there a function to split a string in PL/SQL?
  5. Making a string concatenation operator in R
  6. Removing html tags from a string in R
  7. How to convert variable (object) name into String [duplicate]
  8. Load R package from character string
  9. Getting and removing the first character of a string
  10. pass character strings to ggplot2 within a function
  11. Does xslt have split() function?
  12. Insert a character at a specific location in a string
  13. Convert R vector to string vector of 1 element [duplicate]
  14. as.numeric with comma decimal separators?
  15. converting datetime string to POSIXct date/time format in R
  16. How can I remove repeated characters in a string with R?
  17. R split on delimiter (split) keep the delimiter (split)
  18. How to collapse a list of characters into a single string in R
  19. Split a character vector into individual characters? (opposite of paste or stringr::str_c)
  20. T-SQL Split Word into characters
  21. Is there a function to split a string in Oracle PL/SQL?
  22. R split string by symbol
  23. Repeat and concatenate a string N times
  24. scala string.split does not work
  25. Extract the first (or last) n characters of a string
  26. Insert line breaks in long string — word wrap
  27. How to combine multiple character columns into a single column in an R data frame
  28. Split a string every 5 characters
  29. How to split a string by a string in Scala
  30. Split a string column into several dummy variables

Leave a Comment