hi,

i have a matrix that i want to transform by adding rows that represent the addition of pairs of rows on the matrix. ie, if the matrix is:

0,0,1,1,0,0 0,1,0,0,0,0 0,0,1,0,0,0

the output would be a 6x6 matrix such as

0,0,1,1,0,0 0,1,0,0,0,0 0,0,1,0,0,0 0,1,1,1,0,0 # rows 1+2 0,0,2,1,0,0 # rows 1+3 0,1,1,0,0,0 # rows 2+3

is there an easy way to do this in R without going into nested loops?

thanks!