Count sequences of numbers rowwise

Question

I have the following dataframe with 0, 1, and NAs for IDs A to E over a one year period:

dat <- data.frame(
 id = c("A", "B", "C", "D", "E"),
 jan = c(0, 0, NA, 1, 0),
 feb = c(0, 1, 1, 0, 0),
 mar = c(0, 0, 1, 0, 1),
 apr = c(0, NA, 0, NA, 1),
 may = c(0, NA, 0, 0, 0),
 jun = c(0, 0, 0, 0, 0),
 jul = c(0, 0, 0, 0, 1),
 aug = c(NA, 0, 0, 1, 1),
 sep = c(NA, 0, 0, 1, NA),
 okt = c(NA, 0, 0, 0, NA),
 nov = c(NA, 0, 0, 0, 1),
 dez = c(NA, 0, 0, 0, 0)
)

> dat
  id jan feb mar apr may jun jul aug sep okt nov dez
   A   0   0   0   0   0   0   0  NA  NA  NA  NA  NA
   B   0   1   0  NA  NA   0   0   0   0   0   0   0
   C  NA   1   1   0   0   0   0   0   0   0   0   0
   D   1   0   0  NA   0   0   0   1   1   0   0   0
   E   0   0   1   1   0   0   1   1  NA  NA   1   0

I would like to count the number of 1s for each ID over this one year period, but the following conditions need to be met:

The first occurrence of a 1 is always counted as 1
NAs should be treated as 0s
A second occurrence of a 1 is only counted, if it is preceded by six or more 0s/NAs

In my example, the count would be:

> dat
   id jan feb mar apr may jun jul aug sep okt nov dez     count
 1  A   0   0   0   0   0   0   0  NA  NA  NA  NA  NA      => 0
 2  B   0   1   0  NA  NA   0   0   0   0   0   0   0      => 1
 3  C  NA   1   1   0   0   0   0   0   0   0   0   0      => 1
 4  D   1   0   0  NA   0   0   0   1   1   0   0   0      => 2
 5  E   0   0   1   1   0   0   1   1  NA  NA   1   0      => 1

The function should be applied rowwise in the form of apply(dat[, -1], 1, my_fun) and return a vector containing the count (i.e. 0, 1, 1, 2, 1). Does anybody have an idea how to achieve this?

Count sequences of numbers rowwise

4 Answers