Count the number of appeareances in a list, trick? - r

Question

I have a matrix of 1 and 0. The rules concerning this table is as follows.
I would like to count the number of times a serie of 1,1 appears (where the 1 are not separated by 0!) and make the same thing for a serie of 1,1,1. I have tried colSums but it's seemed not to be very appropriate.
the matrix final is
t1 t2 t3 t4 t5 t6 t7
[1,] 0 0 0 0 1 1 0
[2,] 0 0 1 1 0 0 1
[3,] 1 1 0 0 0 0 0
[4,] 0 0 1 1 1 0 0
[5,] 0 0 1 1 0 0 0
[6,] 1 1 0 0 0 0 0
[7,] 0 0 0 0 0 0 1
[8,] 0 0 0 0 1 1 0
[9,] 1 1 0 0 1 1 0
[10,] 0 0 0 0 0 1 1
[11,] 1 1 0 0 0 0 0
[12,] 0 0 1 1 0 0 0
[13,] 0 0 0 0 0 0 0
[14,] 0 0 0 0 0 0 1
[15,] 0 0 0 0 0 0 0
Therefore for the first row I would like to have 1 time a serie of 1,1 and 0 time a serie of 1,1,1. For row 4 I would like to have 0 time a serie of 1,1 but 1 time a serie of 1,1,1.
Can anyone tell me whats wrong with the following code for a serie of 1,1?
occ <- matrix()
occ_temp <- matrix
for (j in 1:nrow(final)){
for (i in 2:7){
if (sum(final[j,i-1:i])==2){occ_temp[j,i-1]=1}
}
occ[j] <- sum(occ_temp)
}

Answer 1

We can loop through the rows with apply, get the run-length-type with rle, extract the lengths where the values are 1, check that are equal to 'n1' and 'n2', and get the sum.
n1 <- 2
n2 <- 3
res <- t(apply(m1, 1, FUN=function(x) {
x1 <- with(rle(x), lengths[!!values])
c(sum(x1==n1), sum(x1==n2))
}))
colnames(res) <- paste0("count", c(11, 111))
res
# count11 count111
# [1,] 1 0
# [2,] 1 0
# [3,] 1 0
# [4,] 0 1
# [5,] 1 0
# [6,] 1 0
# [7,] 0 0
# [8,] 1 0
# [9,] 2 0
#[10,] 1 0
#[11,] 1 0
#[12,] 1 0
#[13,] 0 0
#[14,] 0 0
#[15,] 0 0