fastpeRmute
vignette.RmdfastpeRmute: Fast Combinations and Permutations in R
The fastpeRmute package offers efficient functions for computing combinations and permutations with and without repetition in R. It is tailored for high performance and provides functionality that can be faster than both base R and the gtools package.
Installation
To install the latest development version from GitHub:
devtools::install_github("gi0na/fastpeRmute")Examples
Combinations
Without Repetition
Load the library:
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ dplyr 1.1.4 ✔ readr 2.1.5
## ✔ forcats 1.0.0 ✔ stringr 1.5.1
## ✔ ggplot2 3.5.1 ✔ tibble 3.2.1
## ✔ lubridate 1.9.3 ✔ tidyr 1.3.1
## ✔ purrr 1.0.2
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag() masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errorsCompute combinations without repetition:
combinations(n = 10, r = 4)## # A tibble: 210 × 4
## V1 V2 V3 V4
## <int> <int> <int> <int>
## 1 1 2 3 4
## 2 1 2 3 5
## 3 1 2 3 6
## 4 1 2 3 7
## 5 1 2 3 8
## 6 1 2 3 9
## 7 1 2 3 10
## 8 1 2 4 5
## 9 1 2 4 6
## 10 1 2 4 7
## # ℹ 200 more rowsWith Repetition
Compute combinations with repetition:
combinations(n = 10, r = 4, repeats.allowed = T)## # A tibble: 715 × 4
## V1 V2 V3 V4
## <int> <int> <int> <int>
## 1 1 1 1 1
## 2 1 1 1 2
## 3 1 1 1 3
## 4 1 1 1 4
## 5 1 1 1 5
## 6 1 1 1 6
## 7 1 1 1 7
## 8 1 1 1 8
## 9 1 1 1 9
## 10 1 1 1 10
## # ℹ 705 more rowsPermutations
Without Repetition
Compute permutations without repetition:
permutations(n = 4, r = 2)## V1 V2
## [1,] 1 2
## [2,] 2 1
## [3,] 1 3
## [4,] 3 1
## [5,] 1 4
## [6,] 4 1
## [7,] 2 3
## [8,] 3 2
## [9,] 2 4
## [10,] 4 2
## [11,] 3 4
## [12,] 4 3With Repetition
Compute permutations with repetition:
permutations(n = 4, r = 2, repeats.allowed = T)## V1 V2
## [1,] 1 1
## [2,] 1 2
## [3,] 1 3
## [4,] 1 4
## [5,] 2 1
## [6,] 2 2
## [7,] 2 3
## [8,] 2 4
## [9,] 3 1
## [10,] 3 2
## [11,] 3 3
## [12,] 3 4
## [13,] 4 1
## [14,] 4 2
## [15,] 4 3
## [16,] 4 4Using Vectors and Lists
Sometimes, it’s helpful to generate combinations or permutations of specific objects.
Combinations from a Vector
Using the built-in letters vector:
v = letters
combinations(v=v, r = 3)## # A tibble: 2,600 × 3
## V1 V2 V3
## <chr> <chr> <chr>
## 1 a b c
## 2 a b d
## 3 a b e
## 4 a b f
## 5 a b g
## 6 a b h
## 7 a b i
## 8 a b j
## 9 a b k
## 10 a b l
## # ℹ 2,590 more rowsPermutations from a Vector
Generate permutations from the letters vector:
v = letters[1:4]
permutations(v=v, r = 2)## V1 V2
## [1,] "a" "b"
## [2,] "b" "a"
## [3,] "a" "c"
## [4,] "c" "a"
## [5,] "a" "d"
## [6,] "d" "a"
## [7,] "b" "c"
## [8,] "c" "b"
## [9,] "b" "d"
## [10,] "d" "b"
## [11,] "c" "d"
## [12,] "d" "c"Combinations from a List
v <- mapply(v1 = letters[1:4], v2 = sample(LETTERS)[1:4], FUN = function(v1, v2) c(v1, v2), SIMPLIFY = FALSE)
combinations(v=v, r = 3, out_format = 'tibble')## # A tibble: 4 × 3
## V1 V2 V3
## <list> <list> <list>
## 1 <chr [2]> <chr [2]> <chr [2]>
## 2 <chr [2]> <chr [2]> <chr [2]>
## 3 <chr [2]> <chr [2]> <chr [2]>
## 4 <chr [2]> <chr [2]> <chr [2]>Permutations from a List
permutations(v=v, r = 2, out_format = 'tibble')## # A tibble: 12 × 2
## V1 V2
## <list> <list>
## 1 <chr [2]> <chr [2]>
## 2 <chr [2]> <chr [2]>
## 3 <chr [2]> <chr [2]>
## 4 <chr [2]> <chr [2]>
## 5 <chr [2]> <chr [2]>
## 6 <chr [2]> <chr [2]>
## 7 <chr [2]> <chr [2]>
## 8 <chr [2]> <chr [2]>
## 9 <chr [2]> <chr [2]>
## 10 <chr [2]> <chr [2]>
## 11 <chr [2]> <chr [2]>
## 12 <chr [2]> <chr [2]>Contributions & Feedback
Feel free to raise issues, contribute to the codebase, or provide any feedback about the package on our GitHub repository.