roundwork
Rounding Infrastructure
Flexible rounding functions for use in error detection, including the exact rounding bounds that consistency tests are built on. They were outsourced from the 'scrutiny' package, which depends on them since its version 1.0.0.
roundwork
The goal of roundwork is to enable flexible rounding beyond
base::round(). Its main API is reround(), from which all implemented
rounding procedures can be accessed. This is useful to reconstruct how
others may have rounded their data.
Given a rounded number, call unround() to get the lower and upper
bounds of the original number. This also takes rounding options into
account, just like reround() does. bound_numerators() and
sum_range() are building blocks using exact integer arithmetic to
avoid all the bugs that can occur with floating-point operations.
roundwork contains the rounding layer that used to be part of scrutiny. Since version 1.0.0, scrutiny imports it from here, as can any other package that reconstructs rounding.
Installation
Install the package from CRAN:
install.packages("roundwork")
Alternatively, install the development version from GitHub:
remotes::install_github("lhdjung/roundwork")
Get started
Round in some specific way, e.g., up from 5:
round_up(4.1679, digits = 2)
#> [1] 4.17
Use reround() to round more flexibly, especially in your own
functions. You can specify a rounding procedure:
reround(4.1679, digits = 2, rounding = "up")
#> [1] 4.17
Ceil or floor numbers if certain strong assumptions are permitted:
reround(4.1679, digits = 2, rounding = "floor")
#> [1] 4.16
The default is to return two numbers — one rounded up, one rounded down. This is best for conservative assumptions, so that your conclusions won’t hinge on edge cases where these rounding procedures differ.
reround(1.275, digits = 2)
#> [1] 1.28 1.27
Ties
“Up” and “down” mean up and down on the number line, so they only part company with “away from zero” and “toward zero” below zero. If you would rather not have to keep that straight, name the tie-breaking rule outright:
round_ties_up(-2.5) # Stata
#> [1] -2
round_ties_away(-2.5) # Excel, SPSS, SAS, Matlab
#> [1] -3
Bounds on the unrounded number
unround() computes the range of an unknown original number, given its
rounded version. The rounding procedure determines whether the bounds
are inclusive or not:
unround("3.60")
#> # A tibble: 1 × 7
#> range rounding lower incl_lower x incl_upper upper
#> <chr> <chr> <dbl> <lgl> <chr> <lgl> <dbl>
#> 1 3.595 <= x(3.60) <= 3.605 up_or_down 3.60 TRUE 3.60 TRUE 3.60
unround("3.60", rounding = "up")
#> # A tibble: 1 × 7
#> range rounding lower incl_lower x incl_upper upper
#> <chr> <chr> <dbl> <lgl> <chr> <lgl> <dbl>
#> 1 3.595 <= x(3.60) < 3.605 up 3.60 TRUE 3.60 FALSE 3.60
unround("3.60", rounding = "ceiling")
#> # A tibble: 1 × 7
#> range rounding lower incl_lower x incl_upper upper
#> <chr> <chr> <dbl> <lgl> <chr> <lgl> <dbl>
#> 1 3.59 < x(3.60) <= 3.6 ceiling 3.59 FALSE 3.60 TRUE 3.6