Dataset before extension: [ 0 -1 -2 -3 -4 -5 -6 ] [ 0 0 0 0 0 0 0 ] [ 0 1 2 3 4 5 6 ] [ 0 2 4 6 8 10 12 ] Dataset after extension: [ 0 -1 -2 -3 -4 -5 -6 7 8 9 ] [ 0 0 0 0 0 0 0 7 8 9 ] [ 0 1 2 3 4 5 6 7 8 9 ] [ 0 2 4 6 8 10 12 7 8 9 ] [ 0 1 2 3 4 5 6 7 8 9 ] [ 0 1 2 3 4 5 6 7 8 9 ]