Format a number in Indian currency format - r

Question

Indian currency format uses a comma separator after every 2 digits, except for the last section which is 3 digits. Can one suggest a function in R that can achieve that.
Example:
input 12345678.23 output 1,23,45,678.23
i/p: 4356, o/p: 4,356
i/p: 435, o/p: 435

Answer 1

I don't know of any native way to do this, but the following function will achieve it for you:
nums <- function(n) {
dec <- round(n %% 1, 2)
dec <- ifelse(dec < 0.01, "", substr(dec, 2, 4))
int <- n %/% 1
ints <- vapply(int, function(x) {
x <- as.character(x)
len <- nchar(x)
if(len <= 3) return(x)
rev_x <- paste(rev(unlist(strsplit(x, ""))), collapse = "")
str <- paste0(substr(rev_x, 1, 3), ",")
str2 <- substr(rev_x, 4, 100)
str2 <- gsub("(\\d{2})", "\\1,", str2)
rev_x <- paste0(str, str2)
return(paste(rev(unlist(strsplit(rev_x, ""))), collapse = ""))
}, character(1))
return(sub("^,", "", paste0(ints, dec)))
}
You can use it like this:
nums(c(1234.12, 342, 35123251.12))
#> [1] "1,234.12" "342" "3,51,23,251.12"

Answer 2

Here might be one option
f <- Vectorize(function(x, digits = 2) {
r <- ""
if (grepl(".", x, fixed = TRUE)) {
r <- c(sub(".*(?=\\.)", "", x, perl = TRUE))
x <- sub("\\..*", "", x)
}
n <- nchar(x)
r <- paste0(substr(x, n - 2, n), r)
x <- substr(x, 1, n - 3)
while (nchar(x)) {
n <- nchar(x)
r <- c(substr(x, n - 1, n), r)
x <- substr(x, 1, n - 2)
}
paste0(r, collapse = ",")
})
and you will see
> f(c(12345678.23, 4356, 435, 900425, 1230010.45))
[1] "1,23,45,678.23" "4,356" "435" "9,00,425"
[5] "12,30,010.45"