[R] Puzzled by results from base::rank()

[Chris Evans]

I understand that the default ties.method is "average".  Here is what I 
get, expanding a bit on the help page example. Running R 4.3.1 on Ubuntu 
22.04.2.

 > x2 <- c(3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5)
 > rank(x2)
  [1]  4.5  1.5  6.0  1.5  8.0 11.0  3.0 10.0  8.0  4.5  8.0

OK so the ties, each of with two members, are ranked to their mean.

So now I turn one tie from a twin to a triplet:

 > x3 <- c(x2, 3)
 > rank(x3)
  [1]  5.0  1.5  7.0  1.5  9.0 12.0  3.0 11.0  9.0  5.0  9.0  5.0
 > sprintf("%4.3f", rank(x3))
  [1] "5.000"  "1.500"  "7.000"  "1.500"  "9.000"  "12.000" "3.000"  
"11.000"
  [9] "9.000"  "5.000"  "9.000"  "5.000"

The doublet is still given the mean of the values but the triplet is 
rounded up.  What am I missing here?!

TIA,

Chris

-- 
Chris Evans (he/him)
Visiting Professor, UDLA, Quito, Ecuador & Honorary Professor, 
University of Roehampton, London, UK.
Work web site: https://www.psyctc.org/psyctc/
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Personal site: https://www.psyctc.org/pelerinage2016/