revcode: Reverse code a numeric variable

In stevemisc: Steve's Miscellaneous Functions

Reverse code a numeric variable

Description

revcode allows you to reverse code a numeric variable. If, say, you have a Likert item that has values of 1, 2, 3, 4, and 5, the function inverts the scale so that 1 = 5, 2 = 4, 3 = 3, 4 = 2, and 5 = 1.

Usage

revcode(x)

Arguments

x	a numeric vector

Details

This function passes over NAs you may have in your variable. It does assume, reasonably might I add, that the observed values include both the minimum and the maximum. This is usually the case in a discrete ordered-categorical variable (like a Likert item). It also assumes that the numeric vector supplied to it contains all possible values and that the minimum observed value is 1. This is usually a safe assumption in survey data where the variable of interest is ordinal (either on a 1:4 scale, or 1:5 scale, or 1:10 scale). No matter, use the function with that in mind.

Value

The function returns a numeric vector that reverse codes the the numeric vector that was supplied to it.

Examples

data.frame(x1 = rep(c(1:7, NA), 2),
      x2 = c(1:10, 1:4, NA, NA),
     x3 = rep(c(1:4), 4)) -> example_data

library(dplyr)
library(magrittr)

example_data %>% mutate_at(vars("x1", "x2", "x3"), ~revcode(.))

stevemisc documentation built on Sept. 11, 2024, 5:23 p.m.