I see a bug in the code. Columns 14 and 17 do not appear to be working. If the vector values are replaced with 524251 (which is the sum of 2^0 through 2^18) we should get 9 rows of 19 shiny spheres, but we get 9 rows of 17 shiny spheres with the spheres at positions 14 and 17 missing from each row. Can anybody say why this might be?