Question

If I have a matrix that is iterated horizontally and then vertically it would enumerate like this:

    0  1  2  3  4  5  6  7  8  9
   ------------------------------
0 |  1  2  3  4  5  6  7  8  9 10
1 | 11 12 13 14 15 16 17 18 19 20
2 | 21 22 23 24 25 26 27 28 29 30

if I want to enumerate vertically I could do this:

  total_rows * coln+ rown+ 1

   0 1 2  3  4  5  6  7  8  9
  --------------------------
0 |1 4 7 10 13 16 19 22 25 28
1 |2 5 8 11 14 17 20 23 26 29
2 |3 6 9 12 15 18 21 24 27 30

anybody have the algorithm handy to enumerate grouped columns vertically?

    ????

    0  1  2  3  4  5  6  7  8  9
   ------------------------------
 0 |1  2  7  8 13 14 19 20 25 26
 1 |3  4  9 10 15 16 21 22 27 28
 2 |5  6 11 12 17 18 23 24 29 30

Answer 1

cols_per_group=2;

(total_rows*cols_per_group)*((int)(coln/cols_per_group))
+(coln%cols_per_group)+cols_per_group*rown +1

i.e. (total size of group)*(which group you’re in)
+ (horizontal position in group) + (width of group) * (vertical position in group) +1