na_if: Convert values to NA

In olascodgreat/samife: A Grammar of Data Manipulation

Description

This is a translation of the SQL command NULL_IF. 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 scoped variants of mutate
# like mutate_if to mutate multiple columns
starwars %>%
  mutate_if(is.character, funs(na_if(., "unknown")))

olascodgreat/samife documentation built on May 13, 2019, 6:11 p.m.