9 parity()

The function parity() determines whether a number is even or odd. This function and its related functions is.even() and is.odd() are inspired by Julia’s iseven() and isodd() functions.⁵ The get_even() and get_odd() functions subset a vector for its even and odd numbers respectively.

parity(mtcars$carb)

##  [1] "even" "even" "odd"  "odd"  "even" "odd"  "even" "even" "even" "even"
## [11] "even" "odd"  "odd"  "odd"  "even" "even" "even" "odd"  "even" "odd" 
## [21] "odd"  "even" "even" "even" "even" "odd"  "even" "even" "even" "even"
## [31] "even" "even"

is.even(1)

## [1] FALSE

is.even(mtcars$carb)

##  [1]  TRUE  TRUE FALSE FALSE  TRUE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE FALSE
## [13] FALSE FALSE  TRUE  TRUE  TRUE FALSE  TRUE FALSE FALSE  TRUE  TRUE  TRUE
## [25]  TRUE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE

is.odd(2)

## [1] FALSE

is.odd(mtcars$carb)

##  [1] FALSE FALSE  TRUE  TRUE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE  TRUE
## [13]  TRUE  TRUE FALSE FALSE FALSE  TRUE FALSE  TRUE  TRUE FALSE FALSE FALSE
## [25] FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE

get_odd(mtcars$carb)

##  [1] 1 1 1 3 3 3 1 1 1 1

get_even(mtcars$carb)

##  [1] 4 4 2 4 2 2 4 4 4 4 4 2 2 2 4 2 2 2 4 6 8 2

---

5. https://libguides.library.kent.edu/SPSS/RecodeVariables↩︎