drake_recursive_contact_state.sh

$ bazel run //examples/instability:py/plant_hidden_state_test
...
[ good 0 ]
Setup(discrete_plant=False, add_contact_viz=True, add_zoh=True, add_latch=True, clean_plant_state=False)

Initialize: 0
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.125]
Initialize: 1
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Post-Init
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Run
  t: 0.0001
  x_a: [0.125 0.   ]
  u: [-0.]
  t: 0.0006000000000000001
  x_a: [0.125 0.   ]
  u: [-0.]
  t: 0.0031000000000000003
  x_a: [0.125 0.   ]
  u: [-0.]
  t: 0.015600000000000001
  x_a: [0.125 0.   ]
  u: [-0.]
  t: 0.0781
  x_a: [0.125 0.   ]
  u: [-0.]
  t: 0.1781
  x_a: [0.125 0.   ]
  u: [-0.]
  t: 0.25
  x_a: [0.125 0.   ]
  u: [-0.]
Good!

[ good 1 ]
Setup(discrete_plant=True, add_contact_viz=False, add_zoh=True, add_latch=True, clean_plant_state=False)

Initialize: 0
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.125]
Initialize: 1
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Post-Init
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Run
  t: 0.25
  x_a: [0.125 0.   ]
  u: [-0.]
Good!

[ good 2 ]
Setup(discrete_plant=True, add_contact_viz=True, add_zoh=False, add_latch=True, clean_plant_state=False)

Initialize: 0
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Initialize: 1
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Post-Init
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Run
  t: 0.25
  x_a: [0.125 0.   ]
  u: [-0.]
Good!

[ good 3 ]
Setup(discrete_plant=True, add_contact_viz=True, add_zoh=True, add_latch=False, clean_plant_state=False)

Initialize: 0
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Initialize: 1
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Post-Init
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Run
  t: 0.25
  x_a: [0.125 0.   ]
  u: [-0.]
Good!

[ good 4 ]
Setup(discrete_plant=True, add_contact_viz=True, add_zoh=True, add_latch=True, clean_plant_state=True)

Initialize: 0
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.125]
Initialize: 1
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Post-Init
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Run
  t: 0.25
  x_a: [0.125 0.   ]
  u: [-0.]
Good!

[ bad ]
Setup(discrete_plant=True, add_contact_viz=True, add_zoh=True, add_latch=True, clean_plant_state=False)

Initialize: 0
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.125]
Initialize: 1
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Post-Init
  t: 0.0
  x_a: [0.125 0.   ]
  u: [-0.]
Run
  t: 0.25
  x_a: [ 0.1171875 -0.03125  ]
  u: [-0.]
Failed as expected: BadVelocity()