Split a vector by its sequences [duplicate]

Answer 1

split(x, cumsum(c(TRUE, diff(x)!=1)))
#$`1`
#[1] 7
#
#$`2`
#[1] 1 2 3 4
#
#$`3`
#[1] 6 7
#
#$`4`
#[1] 9

Answer 2

Just for fun, you can make use of Carl Witthoft's seqle function from his "cgwtools" package. (It's not going to be anywhere near as efficient as Roland's answer.)

library(cgwtools)

## Here's what seqle does...
## It's like rle, but for sequences
seqle(x)
# Run Length Encoding
#   lengths: int [1:4] 1 4 2 1
#   values : num [1:4] 7 1 6 9

y <- seqle(x)
split(x, rep(seq_along(y$lengths), y$lengths))
# $`1`
# [1] 7
# 
# $`2`
# [1] 1 2 3 4
# 
# $`3`
# [1] 6 7
# 
# $`4`
# [1] 9