# Data Fields

HDF5 arrays are loaded sample-first by `src/sparsewake/data.py`.

| Field | Loaded shape | Description |
|---|---:|---|
| `X_raw` | `[N, 6, 3]` | Wake-plus-potential per-sensor induced velocity features. |
| `X_wake_raw` | `[N, 6, 3]` | Wake-only component where available. |
| `X_potential_raw` | `[N, 6, 3]` | Potential-only component where available. |
| `X_external_raw` | `[N, 6, 3]` | External neighbor signal in self-signal datasets. |
| `X_self_raw` | `[N, 6, 3]` | Self-generated signal in self-signal datasets. |
| `X_total_raw` | `[N, 6, 3]` | External-plus-self signal in self-signal datasets. |
| `y` | `[N, 6]` | `delta_x`, `delta_y`, `theta_rel`, `sin_phi`, `cos_phi`, `phi`. |
| `groups` | `[N]` | Wake phase index. |
| `pose_id` | `[N]` | Pose index for pose-holdout when present; otherwise derived from phase blocks. |
| `region_id` | `[N]` | Region code: 1 close wake, 2 near side, 3 mid wake. |
| `sensor_world_positions` | `[N, 6, 2]` | Sensor coordinates for each sample. |

Raw velocity feature channels are body-frame `u`, body-frame `v`, and speed magnitude.