IS to select slice from 3D DMDA vector : 
IS Object: 2 MPI processes
  type: general
[0] Number of indices in set 8
[0] 0 4
[0] 1 5
[0] 2 6
[0] 3 7
[0] 4 20
[0] 5 21
[0] 6 22
[0] 7 23
[1] Number of indices in set 8
[1] 0 36
[1] 1 37
[1] 2 38
[1] 3 39
[1] 4 52
[1] 5 53
[1] 6 54
[1] 7 55

 Extracted slice vector, in DMDA ordering : 
Vec Object: 2 MPI processes
  type: mpi
Process [0]
-6.
-3.
0.
3.
94.
97.
100.
103.
Process [1]
194.
197.
200.
203.
294.
297.
300.
303.

 Extracted slice vector, in natural ordering : 
Vec Object: 2 MPI processes
  type: mpi
Process [0]
-6.
-3.
0.
3.
94.
97.
100.
103.
Process [1]
194.
197.
200.
203.
294.
297.
300.
303.