Round to nearest value, ties away from 0

Round numbers to the nearest whole or decimal value with ties (numbers halfway between two values, i.e., ending in 5) rounding to the nearest value in the direction away from zero.

Usage

round_ties_away(x, digits = 0)

Arguments

x

A numeric vector.

digits

An integer indicating the number of decimal (when positive) or whole number (when zero or negative) places to round x to. The rounding place is equivalent to \(1 / 10^{digits}\). 1 rounds to the nearest tenths place, 0 rounds to the nearest ones place, and -1 rounds to the nearest tens place. (This behaves the same as the digits argument in base::round().)

Value

A numeric vector the same length as x.

Details

base::round() rounds numbers using the "ties to even" method, resulting in both round(1.5) and round(2.5) evaluating to 2. This method attempts to counteract bias in data sets that include numbers that have already been rounded using the "ties away from 0" method (see links below for more detail). Alternatively, round_ties_away() rounds numbers using the "ties away from 0" method, resulting in round_ties_away(1.5) evaluating to 2 and round_ties_away(2.5) evaluating to 3. This may be preferred in some scenarios, e.g., when presenting results.

Code in this function was copied from janitor::round_half_up() (version 2.2.0), which was itself copied from a Stack Overflow forum (see the link below).

Resources:

• Wikipedia entry on Rounding

• Stack Overflow discussion and early source of the function code

Examples

x1 <- seq(-2.5, 2.5, by = 0.5)
x2 <- seq(-0.025, 0.025, by = 0.005)
x3 <- seq(-250, 250, by = 50)

x1
#>  [1] -2.5 -2.0 -1.5 -1.0 -0.5  0.0  0.5  1.0  1.5  2.0  2.5
round(x1)
#>  [1] -2 -2 -2 -1  0  0  0  1  2  2  2
round_ties_away(x1)
#>  [1] -3 -2 -2 -1 -1  0  1  1  2  2  3

x2
#>  [1] -0.025 -0.020 -0.015 -0.010 -0.005  0.000  0.005  0.010  0.015  0.020
#> [11]  0.025
round(x2, digits = 2)
#>  [1] -0.03 -0.02 -0.02 -0.01 -0.01  0.00  0.00  0.01  0.01  0.02  0.03
round_ties_away(x2, digits = 2)
#>  [1] -0.03 -0.02 -0.02 -0.01 -0.01  0.00  0.01  0.01  0.02  0.02  0.03

x3
#>  [1] -250 -200 -150 -100  -50    0   50  100  150  200  250
round(x3, digits = -2)
#>  [1] -200 -200 -200 -100    0    0    0  100  200  200  200
round_ties_away(x3, digits = -2)
#>  [1] -300 -200 -200 -100 -100    0  100  100  200  200  300