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/
CORE site: http://www.coresystemtrust.org.uk/
Personal site: https://www.psyctc.org/pelerinage2016/
Dear Chris, the members of the triplet would be ranked 4, 5 and 6 (in your example), so the *mean of their ranks* is correctly 5. For any set of k tied values the ranks of its elements are averaged (and assigned to each of its k members). Hth -- Gerrit --------------------------------------------------------------------- Dr. Gerrit Eichner Mathematical Institute, Room 215 gerrit.eichner at math.uni-giessen.de Justus-Liebig-University Giessen Tel: +49-(0)641-99-32104 Arndtstr. 2, 35392 Giessen, Germany http://www.uni-giessen.de/eichner --------------------------------------------------------------------- Am 11.08.2023 um 09:54 schrieb Chris Evans via R-help:> 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 >