Rounding in one direction

These functions ignore which neighbor is nearer:

• round_ceiling() always rounds up.

• round_floor() always rounds down.

• round_trunc() always rounds toward zero.

• round_anti_trunc() always rounds away from zero. A value that already sits on the rounding grid stays where it is, so 0 stays 0. This is what Excel's ROUNDUP(), Java's RoundingMode.UP, and Python's decimal.ROUND_UP do.

• anti_trunc() is the counterpart of trunc(): it rounds a number to the nearest whole number away from zero. Whole numbers stay unchanged.

Usage

round_ceiling(x, digits = 0L)

round_floor(x, digits = 0L)

round_trunc(x, digits = 0L)

anti_trunc(x)

round_anti_trunc(x, digits = 0L)

Arguments

x

Numeric. The number to round.

digits

Integer. Number of decimal places to round to. Default is 0. Negative values round to powers of ten.

Value

Numeric. x rounded to digits (anti_trunc() has no digits argument).

Details

round_ceiling(), round_floor(), and round_trunc() generalize ceiling(), floor(), and trunc() to any number of decimal places, and round_anti_trunc() generalizes anti_trunc(). With the default digits = 0, each equals its base counterpart.

round_trunc() is round_floor() for positive and round_ceiling() for negative numbers; round_anti_trunc() is the reverse.

All of these apply the floating-point tolerance described in round_up(), so that round_ceiling(0.28, 2) is 0.28 although 0.28 * 100 is stored as 28.000000000000004.

See also

round_up() and round_down() round to the nearest number and decide ties by a fixed direction.

Examples

round_ceiling(x = 4.52, digits = 1)
#> [1] 4.6
round_floor(x = 4.67, digits = 1)
#> [1] 4.6

round_trunc(8.439, digits = 2)
#> [1] 8.43
round_trunc(-8.439, digits = 2)
#> [1] -8.43

round_anti_trunc(x = 8.421, digits = 2)
#> [1] 8.43
round_anti_trunc(x = -8.421, digits = 2)
#> [1] -8.43