na_if: Convert values to NA

In javifar/TIDYVERSE-DPLYR: A Grammar of Data Manipulation

Description

This is a translation of the SQL command NULLIF. It is useful if you want to convert an annoying value to NA.

Usage

na_if(x, y)

Arguments

x	Vector to modify
y	Value to replace with NA

Value

A modified version of x that replaces any values that are equal to y with NA.

See Also

coalesce() to replace missing values with a specified value.

tidyr::replace_na() to replace NA with a value.

recode() to more generally replace values.

Examples

na_if(1:5, 5:1)

x <- c(1, -1, 0, 10)
100 / x
100 / na_if(x, 0)

y <- c("abc", "def", "", "ghi")
na_if(y, "")

# na_if() is particularly useful inside mutate(),
# and is meant for use with vectors rather than entire data frames
starwars %>%
  select(name, eye_color) %>%
  mutate(eye_color = na_if(eye_color, "unknown"))

# na_if() can also be used with mutate() and across()
# to mutate multiple columns
starwars %>%
   mutate(across(where(is.character), ~na_if(., "unknown")))

javifar/TIDYVERSE-DPLYR documentation built on Dec. 20, 2021, 9:08 p.m.