m <- matrix(1:30, nrow=10)
rownames(m) <- LETTERS[1:10]
colnames(m) <- c('foo', 'bar', 'baz')
m
# foo bar baz
# A 1 11 21
# B 2 12 22
# C 3 13 23
# D 4 14 24
# E 5 15 25
# F 6 16 26
# G 7 17 27
# H 8 18 28
# I 9 19 29
# J 10 20 30