[Rd] base::format adds extraneous whitespace for some inputs

[Sarah Goslee]

I can reproduce this.

It has to do with whether the value rounds down to 9 or up to 10, and
thus needs another space, I think. I agree that it shouldn't happen,
but at least you can get rid of the space by using trim = TRUE.

# rounds to 9 vs 10

format(9.95, digits = 2)
format(9.96, digits = 2)

format(9.95, digits = 2, nsmall = 2)
format(9.96, digits = 2, nsmall = 2)

format(9.95, digits = 2, nsmall = 2, trim=TRUE)
format(9.96, digits = 2, nsmall = 2, trim=TRUE)

# rounds to 99 vs 100

format(99.94, digits = 3)
format(99.95, digits = 3)

format(99.94, digits = 3, nsmall = 2)
format(99.95, digits = 3, nsmall = 2)

format(99.94, digits = 3, nsmall = 2, trim=TRUE)
format(99.95, digits = 3, nsmall = 2, trim=TRUE)


> sessionInfo()
R version 3.5.3 (2019-03-11)
Platform: x86_64-redhat-linux-gnu (64-bit)
Running under: Fedora 28 (Workstation Edition)

Matrix products: default
BLAS/LAPACK: /usr/lib64/R/lib/libRblas.so

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=en_US.UTF-8       LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] colorout_1.2-0

loaded via a namespace (and not attached):
[1] compiler_3.5.3 tools_3.5.3

> # rounds to 9 vs 10
>
> format(9.95, digits = 2)
[1] "9.9"
> format(9.96, digits = 2)
[1] "10"
>
> format(9.95, digits = 2, nsmall = 2)
[1] "9.95"
> format(9.96, digits = 2, nsmall = 2)
[1] " 9.96"
>
> format(9.95, digits = 2, nsmall = 2, trim=TRUE)
[1] "9.95"
> format(9.96, digits = 2, nsmall = 2, trim=TRUE)
[1] "9.96"
>
> # rounds to 99 vs 100
>
> format(99.94, digits = 3)
[1] "99.9"
> format(99.95, digits = 3)
[1] "100"
>
> format(99.94, digits = 3, nsmall = 2)
[1] "99.94"
> format(99.95, digits = 3, nsmall = 2)
[1] " 99.95"
>
> format(99.94, digits = 3, nsmall = 2, trim=TRUE)
[1] "99.94"
> format(99.95, digits = 3, nsmall = 2, trim=TRUE)
[1] "99.95"

On Thu, Jun 20, 2019 at 3:19 AM David J. Birke <djbirke using berkeley.edu> wrote:
>
> Dear R Core Team,
>
> First of all, thank you for your amazing work on developing and
> maintaining this wonderful language.
>
> I just stumbled upon the following behavior in R version 3.6.0:
>
> format(9.91, digits = 2, nsmall = 2)
> format(9.99, digits = 2, nsmall = 2)
>
> yield "9.91" and " 9.99" with an extraneous whitespace.
>
> My expected output for the second command is "9.99".
>
> I have not found anything explaining the whitespace in the help files.
> Therefore, I am writing to report this behavior as a possible bug.
>
> Best wishes,
> David
>
> ______________________________________________
> R-devel using r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel



-- 
Sarah Goslee (she/her)
http://www.numberwright.com