How to repeat a String N times in R?
In Ruby I could repeat a String n times with the following:
E.G. "my_string" * 2 -> "my_stringmy_string"
Is there an equally simple way for doing this in R?
You can use replicate
or rep
:
replicate(2, "my_string")
# [1] "my_string" "my_string"
rep("my_string", 2)
# [1] "my_string" "my_string"
paste
will put it together:
paste(replicate(2, "my_string"), collapse = "")
# [1] "my_stringmy_string"
With R 3.3.0
, we can use strrep
from base R
strrep("my_string",2)
#[1] "my_stringmy_string"
We can also pass a vector of values in times
strrep("my_string",1:3)
#[1] "my_string" "my_stringmy_string"
#[3] "my_stringmy_stringmy_string"
Use stri_dup
function from stringi
package
stri_dup("abc",3)
[1] "abcabcabc"
It is also vectorized, so you can do this:
> stri_dup(letters[1:3],4)
[1] "aaaa" "bbbb" "cccc"
Performance comparision :)
> microbenchmark(stri_dup("abc",3),paste(replicate(3, "abc"), collapse = ""))
Unit: microseconds
expr min lq median uq max neval
stri_dup("abc", 3) 2.362 3.456 7.0030 7.853 64.071 100
paste(replicate(3, "abc"), collapse = "") 57.131 61.998 65.2165 68.017 200.626 100
> microbenchmark(stri_dup("abc",300),paste(replicate(300, "abc"), collapse = ""))
Unit: microseconds
expr min lq median uq max neval
stri_dup("abc", 300) 6.441 7.6995 10.2990 13.757 45.784 100
paste(replicate(300, "abc"), collapse = "") 390.137 419.7740 440.5345 460.042 573.975 100
The stringr
library offers the function str_dup()
:
str_dup("my_string", 2)
[1] "my_stringmy_string"
And it is vectorized over strings and times:
str_dup(c("A", "B", "C"), 2:4)
[1] "AA" "BBB" "CCCC"