hi thanks for your help, im not sure what you meant with your comments but i will look into them...again thanks... And my goal for filling the cells is as you say...the remaining cells just have to be filled with say 60% type 2 en the remaining 40% of cells with type 3. This can be done random or just first 60% type2 and the other type 3. When this is completed i need to make an algorithm that starts swapping celltypes depending on neighbour cells and distances to other cells...i won't go to deep into this but it doesn't matter how the cells in the first stage are filled...just the types 1 are on a own place because they characterize a road which is laid in before the algorithm starts swapping... So can anyone tell how to define the first 60% as type 2 and the remaining cells with type 0 to type 3?? thanks! -- Posted via http://www.ruby-forum.com/.