roman2int {gtools} | R Documentation |
Convert roman numerals to integers
roman2int(roman)
roman |
character vector containing roman numerals |
This function will convert roman numerals to integers without the upper bound imposed by R (3899), ignoring case.
A integer vector with the same length as roman
. Character
strings which are not valid roman numerals will be converted to NA
.
Gregory R. Warnes greg@warnes.net
roman2int(c("I", "V", "X", "C", "L", "D", "M")) # works regardless of case roman2int("MMXVI") roman2int("mmxvi") # works beyond R's limit of 3899 val.3899 <- "MMMDCCCXCIX" val.3900 <- "MMMCM" val.4000 <- "MMMM" as.numeric(as.roman(val.3899)) as.numeric(as.roman(val.3900)) as.numeric(as.roman(val.4000)) roman2int(val.3899) roman2int(val.3900) roman2int(val.4000)