[A] [B] [C]
[A] 1 2 3
[B] 4 5 6
[C] 7 8 9
I have a matrix like above.
I need to change it to
[row] [col] [value]
A A 1
A B 2
A C 3
B A 4
B B 5
...
So the original row names become the first key and original column names become the second key together forming a key. Like (row, col): value structure.
How could I achieve such result?
