Reverse Coding of Variables

Reverses the coding of a vector. Supports numeric, logical, and factor inputs:

• Numeric: Transforms values using min + max - x

• Logical: Flips TRUE/FALSE

• Factor: Reverses the order of levels

Usage

revCode(x, min = NULL, max = NULL, na.rm = FALSE)

Arguments

x

a vector (numeric, logical, or factor).

min

optional numeric minimum. Must be provided together with max. If NULL (default), the observed minimum of x is used.

max

optional numeric maximum. Must be provided together with min. If NULL (default), the observed maximum of x is used.

na.rm

logical; whether to ignore NAs when computing the range (numeric only). If FALSE and NAs are present, a warning is issued and NA is returned for all values. Default is FALSE.

Value

a vector of the same type and length as x, with reversed coding.

Errors

Throws an error if all values are NA, if only one of min/max is provided, if min > max, or if x is not numeric, logical, or factor. A warning is issued if values of x lie outside an explicitly provided [min, max] range.

See also

Other data.recode: asBinary(), combLevels(), dummy(), mReplace(), nf(), recodeX(), stringsAsFactors()

Examples

# Numeric
revCode(c(1, 2, 3, 4, 5))
#> [1] 5 4 3 2 1

# Numeric with explicit range (e.g., Likert scale)
revCode(c(1, 2, 3, 4, 5), min = 1, max = 5)
#> [1] 5 4 3 2 1

# Numeric with NAs
revCode(c(1, 2, NA, 4, 5), na.rm = TRUE)
#> [1]  5  4 NA  2  1

# Logical
revCode(c(TRUE, FALSE, TRUE))
#> [1] FALSE  TRUE FALSE

# Factor
x <- factor(c("low", "medium", "high"), ordered = TRUE)
revCode(x)
#> [1] low    high   medium
#> Levels: medium < low < high