R thousand separator format

Question

I just want to set an option in R that will show all numbers with the thousand localized separator.

I saw many posts that cover the format and formatC, but I need to call the function each time.

formatC(1:10 * 100000, format="d", big.mark=",")

There has to be a solution just like for the digits, such as

options(digits = 5)

Thanks.

The easiest way I can think of would be to add an option to `print.default`. — Rich Scriven, Mar 03 '18 at 21:39

score 4 · Answer 1 · answered Mar 03 '18 at 23:22

A simple workaround could be to define a dedicated function to print numbers with a thousand separator, which could be called, e.g., printT():

printT <- function(x) {formatC(x, format="d", big.mark=",")}

Example:

printT(1:10 * 100000)
[1] "100,000"   "200,000"   "300,000"   "400,000"   "500,000"   "600,000"   "700,000"  
[8] "800,000"   "900,000"   "1,000,000"

score 3 · Accepted Answer · answered Mar 03 '18 at 22:20

3

As mentioned in my comment, the easiest way I can think of would be to add a thousands option to the argument list of print.default and an if() statement in the body.

print.default <- function (x, digits = NULL, quote = TRUE, na.print = NULL, print.gap = NULL, 
                           right = FALSE, max = NULL, useSource = TRUE, thousands = TRUE, ...) 
{
    noOpt <- missing(digits) && missing(quote) && missing(na.print) && 
        missing(print.gap) && missing(right) && missing(max) && 
        missing(useSource) && missing(...)
    if(thousands) {
        return(formatC(x, format="d", big.mark=","))
    }
    .Internal(print.default(x, digits, quote, na.print, print.gap, 
                            right, max, useSource, noOpt))
}

Now we will have to wrap with print, but it works well.

print(1:10 * 100000)
# [1] "100,000"   "200,000"   "300,000"   "400,000"   "500,000"   "600,000"  
# [7] "700,000"   "800,000"   "900,000"   "1,000,000"
print(1:10 * 100000, thousands=FALSE)
# [1] 1e+05 2e+05 3e+05 4e+05 5e+05 6e+05 7e+05 8e+05 9e+05 1e+06

answered Mar 03 '18 at 22:20

Rich Scriven

97,041
11
181
245

That's really nice. Do you think that it would it be possible to easily set and remove the "thousands" option separately instead of passing it as an argument to `print()`? The default value is surely helpful, but I think that it could lead to an unintended use of this option in other cases. – RHertel Mar 03 '18 at 22:30
1

@RHertel - according to [this answer from Roland](https://stackoverflow.com/questions/34638307/changing-how-output-is-printed-to-the-console/34638830#34638830), we would have to re-write code at the C level to change default printing for numerics (and characters). – Rich Scriven Mar 03 '18 at 22:33
1

I see. Thanks. This probably does not qualify as "easily possible" :-) – RHertel Mar 03 '18 at 22:34
thank you Rich! At least it confirms that it wasn't a straight forward solution. – stuski Mar 03 '18 at 22:55

R thousand separator format

2 Answers2