Convert a results matrix to a board
Given a square matrix giving the results of pairwise comparisons, return a board object whose rows show the results of the comparisons.
- A square matrix
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
NAs because a
competitor can't play himself).
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-
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 $i$.
a <- matrix(rpois(25,4),5,5) rownames(a) <- letters[1:5] colnames(a) <- letters[1:5] as.pairwise(a)