Column Capture Frequency

Question

I have a dataset like below

Id        A      B       C
10        1      0       1
11        1      0       1
12        1      1       0
13        1      0       0
14        0      1       1

I am trying to count column patterns as shown below.

 Pattern         Count
 A, C            2
 A, B            1
 A               1
 B, C            1

Not sure where to start, any help or advice is greatly appreciated.

Answer 1

Starting with "reversing" the tabulation of data in two separate vectors:

w = which(dat[-1] == 1L, TRUE)

we could use

table(tapply(names(dat)[-1][w[, "col"]], w[, "row"], paste, collapse = ", "))
#
#   A A, B A, C B, C 
#   1    1    2    1

If the result is not needed just for formatting purposes, in order to avoid the unnecessary paste/ strsplit, the alternative - a lot - is:

pats = split(names(dat)[-1][w[, "col"]], w[, "row"])
upats = unique(pats)
data.frame(pat = upats, n = tabulate(match(pats, upats)))
#   pat n
#1 A, C 2
#3 A, B 1
#4    A 1
#5 B, C 1

Answer 2

If you do not need to group the identifier, simply,

table(apply(df[-1], 1, function(i) paste(names(i[i == 1]), collapse = ',')))

#  A A,B A,C B,C 
#  1   1   2   1 

Answer 3

table(gsub(",*N|N,*", "", chartr('0123', 'NABC', 
         do.call(paste, c(df1[-1] * col(df1[-1]), sep=",")))))

#  A A,B A,C B,C 
#  1   1   2   1 

@DavidArenburg, old/new chartr

cols <- paste(c("N", names(df1[-1])), collapse = "") 
indx <- paste(seq(nchar(cols)) - 1, collapse = "")
table(gsub(",*N|N,*", "", chartr(indx, cols, 
      do.call(paste, c(df1[-1] * col(df1[-1]), sep=",")))))