stri_order: Ordering Permutation


This function finds a permutation which rearranges the strings in a given character vector into the ascending or descending locale-dependent lexicographic order.


stri_order(str, decreasing = FALSE, na_last = TRUE, ..., opts_collator = NULL)



a character vector


a single logical value; should the sort order be nondecreasing (FALSE, default) or nonincreasing (TRUE)?


a single logical value; controls the treatment of NAs in str. If TRUE, then missing values in str are put at the end; if FALSE, they are put at the beginning; if NA, then they are removed from the output


additional settings for opts_collator


a named list with ICU Collator’s options, see stri_opts_collator, NULL for default collation options


For more information on ICU’s Collator and how to tune it up in stringi, refer to stri_opts_collator.

As usual in stringi, non-character inputs are coerced to strings, see an example below for a somewhat non-intuitive behavior of lexicographic sorting on numeric inputs.

This function uses a stable sort algorithm (STL’s stable_sort), which performs up to N*log^2(N) element comparisons, where N is the length of str.

For ordering with regards to multiple criteria (such as sorting data frames by more than 1 column), see stri_rank.


The function yields an integer vector that gives the sort order.


Marek Gagolewski and other contributors


Collation - ICU User Guide,


stri_order(c('hladny', 'chladny'), locale='pl_PL')
## [1] 2 1
stri_order(c('hladny', 'chladny'), locale='sk_SK')
## [1] 1 2
stri_order(c(1, 100, 2, 101, 11, 10))
## [1] 1 6 2 4 5 3
stri_order(c(1, 100, 2, 101, 11, 10), numeric=TRUE)
## [1] 1 3 6 5 2 4