The ut_round() function rounds differently from SAS

[Alex Homel]

Description

The ut_round() function produces unexpected results with options(tplyr.IBMRounding = TRUE).

Tplyr/R/utils.R

Lines 313 to 321 in 6876054

 ut_round <- function(x, n=0) 
 { 
   # x is the value to be rounded 
   # n is the precision of the rounding 
   scale <- 10^n 
   y <- trunc(x * scale + sign(x) * 0.5) / scale 
   # Return the rounded number 
   return(y) 
 } 

Steps to Reproduce

Let's count the mean using a test vector and round it to 3 decimals using ut_round():

> vec <- c(2.64, -3.20, -2.88, 2.95)

> mvec <- mean(vec)

> mvec
[1] -0.1225

> ut_round(mvec, 3)
[1] -0.122

The expected value is -0.123 but I'm getting -0.122

[Michael Stackhouse]

Closed via #126