R provides powerful functions. Apply function is one of them. It keeps you from writing boring loops(while and for). For insance:
# create a matrix of 10 rows x 2 columns
m <-
matrix
(
c
(1:10, 11:20), nrow = 10, ncol = 2)
# divide all values by apply
apply
(m, 1:2,
function
(x) x/2)
Thanks for nsaunders