From arne.henningsen at gmail.com  Sun May 28 17:37:30 2017
From: arne.henningsen at gmail.com (Arne Henningsen)
Date: Sun, 28 May 2017 17:37:30 +0200
Subject: [Rd] Rounding in print.summaryDefault()
Message-ID: <CAMTWbJi22S2+ioQbPYA=L12dDAdrr8BtV_L2pjJ2LgDBk-VLTA@mail.gmail.com>

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
http://www.arne-henningsen.name



[Rd] Rounding in print.summaryDefault()
Arne Henningsen