Hi group, I am trying to right a code to do the following This is how the test file looks like: Chr start end sample1 sample2 chr2 9896633 9896683 0 0 chr2 9896630 9896690 0 0 chr2 14314039 14314098 0 -0.35 chr2 14404467 14404502 0 -0.35 chr2 14421718 14421777 -0.43 -0.35 chr2 16031710 16031769 -0.43 -0.35 chr2 16036178 16036237 -0.43 -0.35 chr2 16048665 16048724 -0.43 -0.35 chr2 37491676 37491735 0 0 chr2 37702947 37703009 0 0 Now I want to summarize the values like Sample Chr Start End Values Probes 1 chr2 9896633 14404502 0 4 1 chr2 14421718 16048724 -0.43 4 1 chr2 37491676 37703001 0 2 2 chr2 9896633 9896690 0 2 2 chr2 14314039 16048724 -0.35 6 2 chr2 37491676 37703009 0 2 Here the start for the first line would be the least value until values are similiar (4) then the end would be highest value. The values is the unique value among the common values. Can I get some ideas or suggestions to perform this because I am new to hard core program in R? waiting for your suggestions, Thanks, Viritha [[alternative HTML version deleted]]