Data presented like this (3 rows with same key 1,2 etc):
k va vb
1 A11 B11
1 A12 B12
1 A13 B13
2 A21 B21
2 A22 B22
2 A23 B23
...
I need to group and transpose each group so I get (dont need keys even)
va1 vb1 va2 vb2 va3 vb3
A11 B11 A12 B12 A13 B13
A21 B21 A22 B22 A23 B23
...