Convert numbers to SI prefix

Question

Is there a R function (or any package) allowing to format numbers (integer) using standard unit prefix (Kilo, Mega etc ...), so

10 -> 10
100 -> 1K
0.01         


        

Answer 1

This is simple to vectorise using case_when from dplyr, and it's much easier on the eyes:

library(dplyr)

si_number = function(x, digits) {

    compress = function(x, n) {
        signif(x * 10^(-n), digits)
    }

    case_when(
        x >= 1e6   ~ paste0(compress(x, 6), "M"),
        x >= 1000  ~ paste0(compress(x, 3), "k"),
        x >= 1     ~ as.character(compress(x, 0)),
        x >= 0.001 ~ paste0(compress(x, -3), "m"),
        x >= 1e-6  ~ paste0(compress(x, -6), "u")
    )
}