Sequentially index between a boolean vector in R [duplicate]

Question

The title says it.

my vector

TF <- c(F,T,T,T,F,F,T,T,F,T,F,T,T,T,T,T,T,T,F)

my desired output

[1] 0 1 2 3 0 0 1 2 0 1 0 1 2 3 4 5 6 7 0 

Answer 1

#with(rle(TF), sequence(lengths) * rep(values, lengths))
with(rle(TF), sequence(lengths) * TF) #Like Rich suggested in comments
# [1] 0 1 2 3 0 0 1 2 0 1 0 1 2 3 4 5 6 7 0

Answer 2

You could use rle() along with sequence().

replace(TF, TF, sequence(with(rle(TF), lengths[values])))
# [1] 0 1 2 3 0 0 1 2 0 1 0 1 2 3 4 5 6 7 0

replace() does the coercion for us.