Looks like you still have some bugs: rewritten data: 1 0 2 3 0 3 first row : 0 0 1 1 0 1 group a : 1 0 1 group b : 2 2 3 Gro

Looks like you still have some bugs: rewritten data: 1 0 2 3 0 3 first row : 0 0 1 1 0 1 group a : 1 0 1 group b : 2 2 3 Group a and group b don't seem to match up with the data. Or I've misunderstood something.