[Rd] Rounding in print.summaryDefault()

Arne Henningsen
2017-05-28T15:37:30Z

Dear all

I am happy that summary.default() no longer rounds since R 3.4.0.

However, in R 3.4.0, in a few cases, print.summaryDefault() rounds the
mean value (and the median value) differently on my GNU/Linux machine
and on my colleague's MS-Windows machine. Here is a small (simplified)
reproducible example:

R> a <- 1234568.01 + c(0:1)
R> summary(a)

Output on MS-Windows (expected rounding of the mean value):
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
1234568 1234568 1234569 1234569 1234569 1234569

Output on GNU/Linux (unexpected rounding of the mean value):
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
1234568 1234568 1234568 1234568 1234569 1234569

The following code gives the same output on MS-Windows and on GNU/Linux:
R> print(summary(a), digits=9)
    Min.   1st Qu.    Median      Mean   3rd Qu.      Max.
1234568.0 1234568.3 1234568.5 1234568.5 1234568.8 1234569.0
R> summary(a)["Mean"]
  Mean
1234569
R> mean(a)
[1] 1234569
R> print(mean(a), digits=9)
[1] 1234568.51

Can these outputs be reproduced by other GNU/Linux and MS-Windows users?

If these differences can be reproduced by others: Should these
differences in the output on GNU/Linux and MS-Windows be considered as
a bug?

Does anybody know how one can avoid to get different roundings in the
outputs of summary() on different computers?

Best,
Arne

--
Arne Henningsen