{
  "schema_version": "affinedrift.ztcf-intervention/v1",
  "intervention_id": "ztcf-planar-golf-python-forward-v1",
  "status": "available",
  "construction": "forward",
  "model": {
    "id": "affinedrift.planar-golf",
    "version": "1.0",
    "source_revision": "524c28926f364631ed06b15be9c6fdf440acce64",
    "engine": "affinedrift-python",
    "engine_version": "GolfModel.ztcf_trajectory/v1",
    "parameters": {
      "masses": [10.0, 5.0, 0.81],
      "lengths": [0.3, 0.35, 1.15],
      "inertias": [0.25, 0.08, 0.089],
      "shaft_mass": 0.3,
      "modal_frequencies": [40.0, 120.0],
      "com_fractions": [0.5, 0.5, 0.5]
    }
  },
  "state": {
    "coordinates": ["q1", "q2", "q3", "qd1", "qd2", "qd3"],
    "frame": "right-handed planar inertial frame; relative joint angles",
    "position_units": "rad",
    "velocity_units": "rad/s",
    "q": [0.2, -0.4, 0.6],
    "qd": [2.0, -1.0, 3.0]
  },
  "zeroed_input": {
    "name": "declared joint-torque vector",
    "physical_level": "applied_generalized_torque",
    "channels": ["shoulder", "elbow", "wrist"],
    "units": "N*m",
    "values": [0.0, 0.0, 0.0]
  },
  "retained": {
    "controls": [],
    "constraints": ["serial three-link planar relative-angle kinematics"],
    "contact": "none",
    "loads": ["uniform gravity at 9.81 m/s^2"],
    "internal_states": [
      "shaft inertia retained through the articulated-body mass matrix",
      "no flexible modal state is integrated by this engine"
    ],
    "parameters": "all values are held at the model record above"
  },
  "integration": {
    "start_time": 0.0,
    "end_time": 0.01,
    "time_units": "s",
    "solver": "fixed-step RK4",
    "solver_version": "GolfModel.ztcf_trajectory/v1",
    "steps": 10,
    "absolute_tolerance": 1e-10
  },
  "expected": {
    "time": 0.01,
    "q": [0.2184078900824315, -0.40823693140190215, 0.6294104732250332],
    "qd": [1.6823945101226174, -0.650410122176964, 2.885420160696207],
    "clubhead_speed": 5.299293488800635,
    "frame": "right-handed planar inertial frame; relative joint angles",
    "position_units": "rad",
    "velocity_units": "rad/s",
    "speed_units": "m/s"
  },
  "interpretation": {
    "simulated_trajectory_difference": "Not estimated by this one-branch replay fixture.",
    "contribution_measure": "No contribution fraction is identified; the fixture verifies deterministic rollout only.",
    "causal_estimand": "Terminal-state response to zeroing the declared torque channel within this exact model.",
    "physiological_interpretation": "Unavailable; generalized-torque removal does not identify muscle activation, force, effort, or intent.",
    "non_identifiability": [
      "individual muscle forces",
      "co-contraction and impedance cost",
      "unmodeled loads or contact changes",
      "human strategy or coaching outcome"
    ]
  },
  "parity": {
    "status": "not_claimed",
    "engines": ["affinedrift-python"],
    "tolerance": null,
    "note": "No second supported engine and no cross-engine parity result are registered."
  },
  "failure": null,
  "preconditions": [
    "the model, source revision, parameters, coordinates, frame, and branch state resolve",
    "the declared torque channel is the only intervention and is set to exactly zero",
    "the retained load, constraint, contact, and internal-state inventory matches the record",
    "the registered Python engine and solver version are available"
  ],
  "postconditions": [
    "the terminal result is expressed in the declared frame and units",
    "the rollout begins from the registered state and ends at the registered horizon",
    "no physiological or cross-engine interpretation is inferred from fixture replay"
  ],
  "failure_states": [
    {
      "code": "invalid_contract",
      "message": "A required model, intervention, state, unit, frame, horizon, or interpretation field is invalid."
    },
    {
      "code": "engine_unavailable",
      "message": "The declared execution engine or version is not installed."
    },
    {
      "code": "engine_unsupported",
      "message": "AffineDrift has no registered adapter for the declared engine or algorithm."
    },
    {
      "code": "numerical_failure",
      "message": "The declared solver cannot produce a finite terminal state at the registered tolerance."
    }
  ]
}