scripts/inference.py

"""Run all PPNN replicas and save the complete verification payload."""

import sys
from pathlib import Path

import numpy as np
import torch
import yaml

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))
from model.ppnn import FORMAT_VERSION, PPNN, ensemble_features


def main():
    config = yaml.safe_load((ROOT / "conf/config.yaml").read_text())
    data = np.load(ROOT / config["data"]["file"])
    checkpoint = torch.load(ROOT / config["paths"]["checkpoint"], map_location="cpu", weights_only=False)
    if str(data["format_version"]) != FORMAT_VERSION or checkpoint.get("format_version") != FORMAT_VERSION:
        raise ValueError("data/checkpoint format version mismatch")
    if data["ensemble"].shape[1:] != (50, 18) or len(data["station_id"]) != 537 or int(data["lead_hours"]) != 48:
        raise ValueError("inference requires 50 members, 18 variables, 537 stations, and 48h lead")
    scaling = checkpoint["scaling"]
    continuous = ensemble_features(torch.from_numpy(data["ensemble"]), torch.from_numpy(data["auxiliary"]))
    continuous = (continuous - scaling["feature_mean"]) / scaling["feature_std"]
    station = torch.from_numpy(data["station_index"])
    mus, sigmas = [], []
    for state in checkpoint["model"]:
        model = PPNN(int(checkpoint["model_config"]["hidden_size"]), eps=float(checkpoint["model_config"]["sigma_epsilon"]))
        model.load_state_dict(state)
        model.eval()
        with torch.no_grad():
            mu_scaled, sigma_scaled = model(continuous, station)
        mus.append(mu_scaled * scaling["target_std"] + scaling["target_mean"])
        sigmas.append(sigma_scaled * scaling["target_std"])
    # The paper averages Gaussian parameters from random networks; this is not a mixture distribution.
    mu = torch.stack(mus).mean(0).numpy()
    sigma = torch.stack(sigmas).mean(0).numpy()
    target = data["target"]
    raw_t2m = data["ensemble"][:, :, 0]
    if not all(np.isfinite(x).all() for x in (mu, sigma, target, raw_t2m)) or not np.all(sigma > 0):
        raise RuntimeError("inference output is non-finite or has non-positive sigma")
    output = ROOT / config["paths"]["inference"]
    output.parent.mkdir(parents=True, exist_ok=True)
    np.savez_compressed(output, mu=mu, sigma=sigma, targets=target, raw_ensemble_t2m=raw_t2m,
                        station_index=data["station_index"], station_id=data["station_id"], date_index=data["date_index"],
                        dates=data["dates"], lead_hours=data["lead_hours"], format_version=np.asarray(FORMAT_VERSION))
    print(f"saved={output.relative_to(ROOT)} samples={len(mu)} replicas={len(mus)} raw_ensemble={raw_t2m.shape}")


if __name__ == "__main__":
    main()