Мы могли бы использовать xtabs
с addmargins
с base R
addmargins(xtabs(count ~ status + species, df), 1)
# species
#status A B C
# Alive 37 6 13
# Dead 17 0 11
# Sum 54 6 24
данные
df <- structure(list(species = c("A", "A", "B", "B", "C", "C"),
status = c("Dead",
"Alive", "Dead", "Alive", "Dead", "Alive"), count = c(17L, 37L,
0L, 6L, 11L, 13L)), .Names = c("species", "status", "count"),
class = "data.frame", row.names = c(NA, -6L))