Tidyverse Book contribution by Rickidon Singh: forcats
forcats is a non-core package in the tidyverse and all the main functions start with fct_ Although you can install forcats using install.packages(“tidyverse”), it is loaded using library(forcats).
library(forcats)as_factor (): Converts an input to a factor. as_factor() is a generic version of as.factor()
Description: Creates levels in the order in which they appear. This ensures means that as_factor(x) will always return the same result, regardless of the current locale.
Usage:
as_factor(x, ...)Example:
x <- c("e", "f", "g")
as_factor(x)## [1] e f g
## Levels: e f gas.factor(x)## [1] e f g
## Levels: e f gfct_c (): Concatenate factors, combining levels.
Description: Allows the patching of factors having both different levels and are of different sources.
Usage:
fct_c(...)Example:
fr <- factor("r")
fs <- factor("s")
frs <- factor(c("r", "s"))
c(fr, fs, frs)## [1] 1 1 1 2fct_c(fr, fs, frs)## [1] r s r s
## Levels: r sfct_count (): Count entries in a factor.
Description: Count entries in a factor.
Usage:
fct_count(f, sort = FALSE)Example:
f <- factor(sample(letters)[rpois(1000, 10)])
table(f)## f
## a b c d e f g h i j k m p q r s v w
## 155 6 92 48 35 115 29 4 73 100 45 121 14 31 93 2 1 6
## x y
## 6 24fct_count(f)## # A tibble: 20 x 2
## f n
## <fct> <int>
## 1 a 155
## 2 b 6
## 3 c 92
## 4 d 48
## 5 e 35
## 6 f 115
## 7 g 29
## 8 h 4
## 9 i 73
## 10 j 100
## 11 k 45
## 12 m 121
## 13 p 14
## 14 q 31
## 15 r 93
## 16 s 2
## 17 v 1
## 18 w 6
## 19 x 6
## 20 y 24fct_count(f, sort = TRUE)## # A tibble: 20 x 2
## f n
## <fct> <int>
## 1 a 155
## 2 m 121
## 3 f 115
## 4 j 100
## 5 r 93
## 6 c 92
## 7 i 73
## 8 d 48
## 9 k 45
## 10 e 35
## 11 q 31
## 12 g 29
## 13 y 24
## 14 p 14
## 15 b 6
## 16 w 6
## 17 x 6
## 18 h 4
## 19 s 2
## 20 v 1fct_drop (): ALlows you to drop unused levels.
Description: In comparison to base::droplevels(), does not drop NA levels that have values.
Usage:
fct_drop(f, only)Example:
f <- factor(c("a", "b"), levels = c("a", "b", "c"))
f## [1] a b
## Levels: a b cfct_drop(f)## [1] a b
## Levels: a b#Restrict which levels to drop
fct_drop(f, only = "a")## [1] a b
## Levels: a b cfct_drop(f, only = "c")## [1] a b
## Levels: a bfct_expand (): Add additional levels to a factor.
Description: Allows the expansion of levels to a chosen factor.
Usage:
fct_expand(f, ...)Example:
f <- factor(sample(letters[1:3], 20, replace = TRUE))
f## [1] b b a c a c b a c a c a c b b c c c b c
## Levels: a b cfct_expand(f, "d", "e", "f")## [1] b b a c a c b a c a c a c b b c c c b c
## Levels: a b c d e ffct_expand(f, letters[1:6])## [1] b b a c a c b a c a c a c b b c c c b c
## Levels: a b c d e ffct_explicit_na (): Make missing values explicit.
Description: Provides missing value an explicit factor level, ensuring that they appear in summaries and on plots.
Usage:
fct_explicit_na(f, na_level = "(Missing)")
Example:
f1 <- factor(c("a", "a", NA, NA, "a", "a", NA, NA, "c", "a", "c", "b"))
table(f1)## f1
## a b c
## 5 1 2f2 <- fct_explicit_na(f1)
table(f2)## f2
## a b c (Missing)
## 5 1 2 4fct_inorder (): Reorder factors levels by first appearance or frequency.
Description: Reorders the factor levels by first appearance or frequency.
Usage:
fct_inorder(f, ordered = NA)
fct_infreq(f, ordered = NA)Example:
f <- factor(c("b", "b", "a", "c", "c", "c"))
f## [1] b b a c c c
## Levels: a b cfct_inorder(f)## [1] b b a c c c
## Levels: b a cfct_infreq(f)## [1] b b a c c c
## Levels: c b afct_inorder(f, ordered = TRUE)## [1] b b a c c c
## Levels: b < a < cfct_other (): Replaces levels with “other.”
Description: Makes it easier to convert selected levels to “other”
Usage:
fct_other(f, keep, drop, other_level = "Other")
Example:
x <- factor(rep(LETTERS[1:9], times = c(40, 10, 5, 27, 1, 1, 1, 1, 1)))
fct_other(x, keep = c("A", "B"))## [1] A A A A A A A A A A A
## [12] A A A A A A A A A A A
## [23] A A A A A A A A A A A
## [34] A A A A A A A B B B B
## [45] B B B B B B Other Other Other Other Other
## [56] Other Other Other Other Other Other Other Other Other Other Other
## [67] Other Other Other Other Other Other Other Other Other Other Other
## [78] Other Other Other Other Other Other Other Other Other Other
## Levels: A B Otherfct_other(x, drop = c("A", "B", "C", "D"))## [1] Other Other Other Other Other Other Other Other Other Other Other
## [12] Other Other Other Other Other Other Other Other Other Other Other
## [23] Other Other Other Other Other Other Other Other Other Other Other
## [34] Other Other Other Other Other Other Other Other Other Other Other
## [45] Other Other Other Other Other Other Other Other Other Other Other
## [56] Other Other Other Other Other Other Other Other Other Other Other
## [67] Other Other Other Other Other Other Other Other Other Other Other
## [78] Other Other Other Other Other E F G H I
## Levels: E F G H I Otherfct_recode (): Change factor levels by hand.
Description: Allows the change of factor levels by hand.
Usage:
fct_recode(.f, ...)Example:
x <- factor(c("canada", "dog", "brazil", "cat"))
fct_recode(x, country = "canada", country = "brazil")## [1] country dog country cat
## Levels: country cat dog# Keep in mind, if you name the level NULL it will be removed
fct_recode(x, NULL = "canada", country = "brazil")## [1] <NA> dog country cat
## Levels: country cat dogfct_relabel(): ALlows the programmatic relabeling of levels.
Description: Automatically relabel factor levels, collapse as necessary.
Usage:
fct_relabel(.f, .fun, ...)Example:
x <- factor(letters[1:3])
x## [1] a b c
## Levels: a b cx %>% fct_relabel(function(x) paste0("-", x, "-"))## [1] -a- -b- -c-
## Levels: -a- -b- -c-fct_relevel (): Reorder factor levels by hand.
Description: Allows you to move any number of levels to any location.
Usage:
fct_relevel(.f, ..., after = 0L)
Example:
f <- factor(c("w", "x", "y", "z"))
fct_relevel(f)## [1] w x y z
## Levels: w x y zfct_relevel(f, "y")## [1] w x y z
## Levels: y w x zfct_relevel(f, "x", "w")## [1] w x y z
## Levels: x w y z# Move to the forth position
fct_relevel(f, "x", after = 3)## [1] w x y z
## Levels: w y z x# 'Inf' allows you to relevel to the end when there is an unknown number of levels
fct_relevel(f, "w", after = Inf)## [1] w x y z
## Levels: x y z w