round_preserve_sum: Round values while preserve their rounded sum in R

In guideR: Miscellaneous Statistical Functions Used in 'guide-R'

Round values while preserve their rounded sum in R

Description

Sometimes, the sum of rounded numbers (e.g., using base::round()) is not the same as their rounded sum.

Usage

round_preserve_sum(x, digits = 0)

Arguments

x	Numerical vector to sum.
digits	Number of decimals for rounding.

Details

This solution applies the following algorithm

• Round down to the specified number of decimal places

• Order numbers by their remainder values

• Increment the specified decimal place of values with k largest remainders, where k is the number of values that must be incremented to preserve their rounded sum

Value

A numerical vector of same length as x.

Source

https://biostatmatt.com/archives/2902

Examples

sum(c(0.333, 0.333, 0.334))
round(c(0.333, 0.333, 0.334), 2)
sum(round(c(0.333, 0.333, 0.334), 2))
round_preserve_sum(c(0.333, 0.333, 0.334), 2)
sum(round_preserve_sum(c(0.333, 0.333, 0.334), 2))

guideR documentation built on June 8, 2025, noon