r - Find correspondent numbers in integer intervals -

i correspondent numbers between 2 integers intervals. input that:

    start1  end1    start2  end2           20     30      25      35       25     35      20      30          100     190    126      226            126     226    100      190      

in first , second line, overlap first(1) interval (2 first collumns) second(2) interval (2 last collumns) equal 6 correspondents numbers (25,26,27,28,29 , 30).

my expected output that:

start1  end1    start2  end2    bp_overlapped       20    30       25      35          6            25    35       20      30          6   100    190     126     226          65   126    226     100     190          65 

it matrix in r.

thank you.

the function searching intersect. can if x first matrix:

f <- function(x)     length( intersect(seq(x[1],x[2],1), seq(x[3],x[4],1)) ) <- apply(x,1,f) x <- cbind(x,a) 

the function apply applies function on each row of matrix (if second argument 1) or on each column (if second argument 2).