DM Object: box 1 MPI process
  type: plex
box in 2 dimensions:
  Number of 0-cells per rank: 15
  Number of 1-cells per rank: 22
  Number of 2-cells per rank: 8
Labels:
  marker: 1 strata with value/size (1 (24))
  Face Sets: 4 strata with value/size (1 (4), 2 (2), 3 (4), 4 (2))
  depth: 3 strata with value/size (0 (15), 1 (22), 2 (8))
  celltype: 3 strata with value/size (0 (15), 1 (22), 4 (8))
 lo = -2. hi = 2. n = 4 h = 1.
 lo = 0. hi = 2. n = 2 h = 1.
DM Object: Particle Grid 1 MPI process
  type: swarm
Particle Grid in 2 dimensions:
  Number of particles per rank: 50
Energy =   5.000000000000e+01 error =   2.131628207280e-15