Arithmetic operations

This generic provides a common double dispatch mechanism for all infix operators (+, -, /, *, ^, %%, %/%, !, &, |). It is used to power the default arithmetic and boolean operators for vctrs objects, overcoming the limitations of the base Ops generic.

Usage

vec_arith(op, x, y, ...)

# S3 method for default
vec_arith(op, x, y, ...)

# S3 method for logical
vec_arith(op, x, y, ...)

# S3 method for numeric
vec_arith(op, x, y, ...)

vec_arith_base(op, x, y)

MISSING()

Arguments

op

An arithmetic operator as a string

x, y

A pair of vectors. For !, unary + and unary -, y will be a sentinel object of class MISSING, as created by MISSING().

...

These dots are for future extensions and must be empty.

Details

vec_arith_base() is provided as a convenience for writing methods. It recycles x and y to common length then calls the base operator with the underlying vec_data().

vec_arith() is also used in diff.vctrs_vctr() method via -.

See also

stop_incompatible_op() for signalling that an arithmetic operation is not permitted/supported.

See vec_math() for the equivalent for the unary mathematical functions.

Examples

d <- as.Date("2018-01-01")
dt <- as.POSIXct("2018-01-02 12:00")
t <- as.difftime(12, unit = "hours")

vec_arith("-", dt, 1)
#> [1] "2018-01-02 11:59:59 UTC"
vec_arith("-", dt, t)
#> [1] "2018-01-02 UTC"
vec_arith("-", dt, d)
#> Time difference of 129600 secs

vec_arith("+", dt, 86400)
#> [1] "2018-01-03 12:00:00 UTC"
vec_arith("+", dt, t)
#> [1] "2018-01-03 UTC"
vec_arith("+", t, t)
#> Time difference of 24 hours

vec_arith("/", t, t)
#> [1] 1
vec_arith("/", t, 2)
#> Time difference of 6 hours

vec_arith("*", t, 2)
#> Time difference of 24 hours