This package is my take on implementing the Verhoeff algorithim for calculating check digits. My influence for the algorithims implementation was primarily from the wikipedia outline (https://en.wikipedia.org/wiki/Verhoeff_algorithm), and the paper by A. Dunn (Computer program for the calculation and validation of Verhoeff check digits, https://www.ccamlr.org/en/wg-fsa-sam-05/11)
You can install verhoeff from CRAN with:
install.packages("verhoeff")Or grab the development version from github with:
devtools::install_github("condwanaland/verhoeff")To calculate the Verhoeff Check Digit for a given number, use
verhoeff_calculate
library(verhoeff)
verhoeff::verhoeff_calculate(123)
#> [1] 3To calculate for many numbers, just pass a vector.
verhoeff_calculate(c(1234, 5678, 9, 10))
#> [1] 0 8 1 9If you would prefer the output to be in a list, with one check digit
per element, use the as_list parameter.
verhoeff_calculate(c(1234, 5678, 9, 10), as_list = TRUE)
#> [[1]]
#> [1] 0
#>
#> [[2]]
#> [1] 8
#>
#> [[3]]
#> [1] 1
#>
#> [[4]]
#> [1] 9The output of verhoeff_calculate is designed so it can
be a new column in a dataframe (i.e., as the output of a
dplyr::mutate call)
suppressPackageStartupMessages(library(dplyr))
# Make a random dataframe that has integer columns
mtcars$name <- rownames(mtcars)
mtcars %>%
select(name, gear) %>%
mutate(check_digit = verhoeff_calculate(gear))
#> name gear check_digit
#> 1 Mazda RX4 4 3
#> 2 Mazda RX4 Wag 4 3
#> 3 Datsun 710 4 3
#> 4 Hornet 4 Drive 3 6
#> 5 Hornet Sportabout 3 6
#> 6 Valiant 3 6
#> 7 Duster 360 3 6
#> 8 Merc 240D 4 3
#> 9 Merc 230 4 3
#> 10 Merc 280 4 3
#> 11 Merc 280C 4 3
#> 12 Merc 450SE 3 6
#> 13 Merc 450SL 3 6
#> 14 Merc 450SLC 3 6
#> 15 Cadillac Fleetwood 3 6
#> 16 Lincoln Continental 3 6
#> 17 Chrysler Imperial 3 6
#> 18 Fiat 128 4 3
#> 19 Honda Civic 4 3
#> 20 Toyota Corolla 4 3
#> 21 Toyota Corona 3 6
#> 22 Dodge Challenger 3 6
#> 23 AMC Javelin 3 6
#> 24 Camaro Z28 3 6
#> 25 Pontiac Firebird 3 6
#> 26 Fiat X1-9 4 3
#> 27 Porsche 914-2 5 8
#> 28 Lotus Europa 5 8
#> 29 Ford Pantera L 5 8
#> 30 Ferrari Dino 5 8
#> 31 Maserati Bora 5 8
#> 32 Volvo 142E 4 3In addition to verhoeff_calculate, verhoeff
offers verhoeff_append and
verhoeff_validate.
Use verhoeff_append to append a check digit to a
provided number:
verhoeff_append(123)
#> [1] "123-3"
verhoeff_append(c(123, 5, 0))
#> [1] "123-3" "5-8" "0-4"Use verhoeff_validate to check whether a check digit is
correct for the provided number
verhoeff_validate(number = 123, check_digit = 3)
#> [1] TRUE
verhoeff_validate(number = 123, check_digit = 4)
#> [1] FALSESee https://github.com/fascinatingfingers/CheckDigit for another implementation of check digits that considers more than just the Verhoeff algorithim.