This is where you're going to have to give us more information about what you actually want. Cadavre's solution produces one row for each distinct value of length and since your new stof13 variable is the only one with a value of 8 then that creates a new row for 8's and only stof13 is populated with it. So, where do you think the stof13 value of 8 should go and why? Because based on your original post a value of 8 does not belong in a row with 6's or 7's. My guess is that somehow balk1 is the key variable that all the stof variables are related to but you haven't told us how they are to be related.