Hi Ivan, Thanks again for your help! I'll just go through your questions...
I'm still really confused about your question. -Sorry!!! Let me ask you some specific questions (maybe someone more experienced would understand at once, but I'm no expert; I hope I can still help you! In any case, I would like to understand for myself ;) ) - is "seal_dist" the name of your data.frame? yes so.. head(seal_dist) FROM TO DIST ID HR DD MM YY ANIMAL DAY 1 1 1 2.63981 'A1' 9 30 9 7 1 1 2 1 2 0.00000 'A1' 9 30 9 7 1 1 3 1 3 6.95836 'A1' 9 30 9 7 1 1 4 1 4 8.63809 'A1' 9 30 9 7 1 1 5 1 1 0.00000 'A1.1' 9 30 9 7 7 1 6 1 2 2.63981 'A1.1' 9 30 9 7 7 1 - what do you want to do with SEL_DAY[i]=dist[i] That was a (desperate) attempt to do 'something', but didn't work - so shouldn't have been in the script I posted, sorry! ? What is "dist"? It is a measure of distance from one point (ID) to another i.e. the distance between A1 and A1.1 If I understand well, you want to replace the values in FROM (then TO, then DIST...) with the values from the same column number in dist? The problem is that Arc doesn't output the data as I'd like, so I want to create a new column to add to the data. What Arc has done is taken a distance between each ID for each hour, but because the number of IDs in each hour don't match it means that the TO number is not unique to the ID throughout the entire dataset, only on that given hour. So when distance = 0 in the TO column then that TO number -s equal to the ID i.e. the distance to A1 to A1 is 0, so I then want to use that information to create a new column that will tell me the actual ID. If that is any clearer? - Since I still haven't understood your goal completely, I still don't understand why you add the column TO_ID to SEL_HR. see above - In any case, a matrix cannot work because you want to store data of different classes in DIST_LOOP (ID is character and the others are numeric). You can either use a data.frame (if you really want to have the table-like structure, which is a list) or a list. I see, can you advise on how to set up a list to write to? - Moreover, the output from dput(your data) would really help to see what you have! I have not long posted it, I hope it helps!! Thanks again for your help Ivan, much appreciated, Ross -- View this message in context: http://r.789695.n4.nabble.com/storing-output-data-from-a-loop-that-has-varying-row-numbers-tp2238396p2238630.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.