-inf 0.0 0.0 0.0
 nan 0.2 0.4 0.6
 inf 0.0 0.0 0.0
  0  0.0 0.0 0.0
  1  0.0 1.0 0.0
  2  0.0 1.0 1.0
  3  1.0 1.0 1.0