data(frogs)
frogs.matrix
is a 9-by-9 matrix with rows and columns
corresponding to 9 stimuli presented to a female frog. Entry
$(i,j)$ corresponds to the number of times the frog preferred
stimulus $i$. Dataset frogs
is a 36-by-9 matrix with each row corresponding
to a pair of distinct stimuli [$36=9*(9-1)/2$]; if a row has
non-NA
columns $i$ and $j$, the its entries show the
number of times the frog preferred stimulus $i$ or stimulus
$j$.
The first form may be converted to the second using function
as.pairwise()
. Note that the square matrix may have NA
entries off the main diagonal (some pairs did not meet).
See purum.Rd
for another type of mating preference dataset.
purum