Avoiding a loop

2011/4/8 Juan Carlos Borr?s <jcborras at gmail.com>:

#Use the indexes of S in a sapply function.

N <- 10
S <- sample(c(0,1), size=N, replace=TRUE)
v1 <- sapply(c(1:N-1), function(i) S[i]&&S[i+1])

You can achieve the same v1 using

v1.2 <- ?S[2:N-1] & S[2:N]

.. or if you insist on having NA as the first element, -- c(NA, v1.2)

Vectorization is more efficient than loops but this need not be true
for the *apply functions.

# Then
v2 <- (P > m)