Subset data frame based on vector sequence of minimum 5 consecutive values

Question

I have a vector that looks like this:

out1[1:200]
  [1] NA NA NA NA  0  1  2 NA NA NA  1 NA  0 NA  0  1 NA NA  0 NA  0  1  2  2  2 NA  0  1  2  3  4  4  5  6  7  8  9  9  9  9
 [41] 10 11 NA  0  0 NA  1 NA  0  1 NA  0 NA  0  1  2 NA  1 NA  0  0  0  1  2 NA NA NA  0  0 NA  0  0  0  1  2 NA  1  2 NA  0
 [81]  1  2  3  4  5  6  7  8 NA  0  1  2  3  4 NA  0  1  2  2  3  4  5 NA  0  1  2  3  3  4  5  5  6  7 NA  1  2 NA  1  2 NA
[121]  0  1  2 NA  1  2  3  3  3  3  4 NA  0  0  0  1  2  3  4  5 NA NA  0  1 NA NA NA  1  2  2  3 NA  1  2  2  2 NA NA  0  1
[161] NA  1 NA  1  2 NA  0  0 NA NA  0  1 NA NA NA NA  1  2  3 NA NA  1  2  3  4  5  6 NA  1  2  3  4  5  6  6  7  8 NA  0  1

I now want to subset a df (with the same length) by this vector, but only sequences that have a range over minimum 5 consecutive numbers, e.g. 0:4, or 1:5 (and of course everything longer than this). Hence, NA's should be FALSE as well.

E.g.

out1: NA NA 0 1 2 2 NA 0 0 1 2 3 3 4 NA 

Then the result should be

out2: F F F F F F F T T T T T T T F

Answer 1

Following gives the desired result

library(data.table) # v >= 1.9.5 (devel version - install from GitHub)
data.table(x)[,id:=rleid(!is.na(x)),
   ][ , aa:=(.N>5) , by = id
      ][ ,aaa:=4 %in% cumsum(diff(unique(sort(x)))), by = .(id, aa)
         ]$aaa

## [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE
## [15]  TRUE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE

---

data

x <- c(NA, NA, NA, NA, NA, 0, 1, 2, NA, 0, 1, 2, 3, 4, 4, 5, NA, 1, 2, 3, 3, 3, 3, 4, NA)