as.pairwise {aylmer} | R Documentation |
Given a square matrix giving the results of pairwise comparisons, return a board object whose rows show the results of the comparisons.
as.pairwise(x)
x |
A square matrix |
With x
an n-by-n square matrix, the rows and
columns each correspond to one of n “competitors”. The
(i,j)-th entry the number of times competitor i beats
competitor j (the leading diagonal holds NA
s because a
competitor can't play himself).
Function as.pairwise()
turns this into a
n(n-1)/2-by-n matrix whose rows each correspond to a
pairwise comparison. Any row has exactly two non-NA
entries,
in columns i and j, that correspond to elements
(i,j) and (j,i) of x
. Thus the entry in column
i is the number of times competitor i beats competitor
j; and the entry in column j is the number of times
competitor j beats competitor i.
Robin K. S. Hankin
a <- matrix(rpois(25,4),5,5) rownames(a) <- letters[1:5] colnames(a) <- letters[1:5] as.pairwise(a)