Predictive draws of the series, (n_paths, steps).
Each path picks a kept draw, then propagates both random-walk
log variances and the trend forward and adds the irregular.
- Parameters:
steps (int) – Horizons ahead, at least 1.
n_paths (int) – Predictive paths.
seed (int | None) – Seed.
- Raises:
SpecificationError – If steps is not positive.
- Return type:
NDArray[double]