Printing numbers with separators in R

20 Feb 2015

I have been working with fairly large numbers in R (though mixed with numbers of “ordinary size”). To help with reading them I wanted thousands and higher separators to be printed. This shows one way to achieve this.

Here is some test data.

    day.counts <- structure(c(128675575, 91892653), .Names = c("day1", "day2"))

These number are large enough that it is easy to miss the actual order between them. When printed using

    print(format(day.counts, big.mark=","), quote=FALSE)

You get

       day1        day2
128,675,575  91,892,653

Clearly showing that the first has one more digit than the second.

When using the magrittr package (for instance through dplyr) you can add this type of printing using

    day.counts %>%
    format(big.mark=",") %>%