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Unified Factor Manipulation

Source: R/fct_cat.R
fct_cat.Rd

One function for all factor operations. Works on vectors (usable in mutate()) and auto-detects the action from arguments.

Usage

fct_cat(
  x,
  ...,
  reverse = FALSE,
  binary_ref = NULL,
  groups = NULL,
  new_labels = NULL,
  combine = NULL,
  sep = " & "
)

Arguments

x

A factor or character vector. For combine mode this is optional – if missing, all columns listed in combine are used.

...

For recode: named args (new = old). For reorder: level names in desired order (unnamed strings). Must be ALL named or ALL unnamed.

reverse

Logical. Reverse all levels? Default FALSE.

binary_ref

Integer index(es) of reference level(s). Others collapse to "Oth".

groups

Named list of integer index vectors for custom grouping, e.g. list(early = 1:2, late = 3:4).

new_labels

Character vector to rename levels (same length as levels).

combine

Character vector of column names to combine. Works inside mutate(). If x is provided, it is combined with the listed columns. If x is missing, all listed columns are combined.

sep

Separator for combine. Default " & ".

Value

A factor.

See also

Other factor tools: fct_num()

Examples

x <- factor(letters[1:6])

# Recode (named ...)
fct_cat(x, AB = c("a","b"), CD = c("c","d"))
#> [1] AB AB CD CD e  f 
#> Levels: AB CD e f
fct_cat(x, g1 = 1:3, g2 = 4:6)
#> [1] g1 g1 g1 g2 g2 g2
#> Levels: g1 g2

# Reorder (unnamed ...)
fct_cat(factor(letters[1:4]), "c", "b")
#> [1] a     d
#> Levels:  a d

# Reverse
fct_cat(factor(letters[1:4]), reverse = TRUE)
#> [1] a b c d
#> Levels: d c b a

# Binary
fct_cat(factor(c("I","II","III","IV")), binary_ref = 1)
#> [1] I   Oth Oth Oth
#> Levels: I Oth

# Group
fct_cat(factor(c("I","II","III","IV")), groups = list(early = 1:2, late = 3:4))
#> [1] early early late  late 
#> Levels: early late

# Relabel
fct_cat(factor(c("I","II","III","IV")), new_labels = c("One","Two","Three","Four"))
#> [1] One   Two   Three Four 
#> Levels: One Two Three Four

# Combine in mutate():
if (FALSE) { # \dontrun{
df %>% mutate(grp = fct_cat(sex, combine = "age"))
df %>% mutate(grp = fct_cat(sex, combine = c("age", "race")))
df %>% mutate(grp = fct_cat(combine = c("sex", "age")))
} # }