Task 5 — Predict-only using previously saved models.
Loads fitted forecasters that were persisted by a prior LazyTask or DefaultsTask run (or by any task in the spotforecast2 sibling package) and produces predictions for all configured targets. No training or tuning is performed.
If no saved models exist in the cache directory the run method raises RuntimeError with an informative message.
Aggregate per-target prediction packages into a weighted forecast.
Delegates to the module-level agg_predictor function. Available as an instance method so that subclasses can override the aggregation strategy when needed.
Build, combine, encode, and merge exogenous feature covariates.
This is step 4-7 of the pipeline (run after prepare_data, detect_outliers, and impute). It assembles the full exogenous-covariate matrix that the forecaster consumes, then merges it onto the target data. The orchestration proceeds in order:
4a — Weather, via get_weather_features (Open-Meteo). The response is parquet-cached only when config.cache_home is set. Fetch failures are handled per config.on_weather_failure: "raise" re-raises WeatherFetchError; "skip" logs a warning and continues with an empty weather frame (fail-safe). When config.zone_weather_columns is set (opt-in, mutually exclusive with per_zone_weather / use_population_weighted_weather), this step instead calls weather.zone_columns.build_zone_weather_columns and concatenates population-weighted weather for each of the four German TSO zones as __<zone_short>-suffixed columns (e.g. temperature_2m__50hertz) for the single target.
4b — Calendar features, via get_calendar_features.
4c — Day/night (solar) features, via get_day_night_features (computed with astral from config.latitude / config.longitude).
4d — Holiday features, via get_holiday_features for config.country_code / config.state.
5 — The four frames are concatenated along the columns and any residual gaps are back- then forward-filled.
4f — Lagged-load exog (opt-in, default OFF, gated by config.include_load_lag_exog), via preprocessing.load_lags.build_load_lag_features. Runs AFTER the Step-5 backfill so a load-lag coverage failure is never masked by it. Appends load_lag_<L> / load_<zone>_lag_<L> / share_<zone>_lag_<L> columns per config.load_lag_hours / config.load_lag_sources. A coverage or staleness failure (or a missing zone-interim file for the "zones"/"zone_shares" sources) is governed by config.on_load_lag_failure: "raise" re-raises; "skip" logs a warning and omits the columns (fail-safe). Provider-based exogenous columns are then appended via build_providers_from_config (requires spotforecast2-safe >= 15.7.0). The active providers are governed by the config flags include_covid_infection_rate, include_entsoe_forecast_load, include_entsoe_renewable_forecast, include_entsoe_net_load, and include_entsoe_day_ahead_price. Cyclical (sine/cosine) encoding is then applied via apply_cyclical_encoding, and degree-config.poly_features_degree interaction terms are added via create_interaction_features. When the degree is at least 2, the polynomial columns are ranked by mutual information with the primary target and capped to config.max_poly_features via select_top_poly_features.
6 — The training feature set is chosen via select_exogenous_features (including, when config.include_day_type_features is set, the day-type columns is_workday / day_type), with provider and load-lag columns appended (order-preserving, de-duplicated).
7 — Targets and covariates are merged via merge_data_and_covariates into self.data_with_exog and the forecast-horizon covariates self.exo_pred.
When config.use_exogenous_features is False the method is a no-op and returns self immediately, leaving the pipeline target-only.
Per-zone weather frames keyed by target name, indexed over [data_start, cov_end] (covering the forecast horizon). Populated only when config.per_zone_weather is True and every zone fetch succeeded; empty otherwise (including the fail-safe “skip” degradation). Consumed at the per-target seam in _get_target_data to overwrite the shared weather columns.
If the Open-Meteo fetch fails (single-point, population-weighted, per-zone, or zone_weather_columns path) and config.on_weather_failure == "raise".
LoadLagError
If config.include_load_lag_exog is set, the load-lag builder cannot produce NaN-free columns (stale source, excessive staleness), and config.on_load_lag_failure == "raise".
If config.include_load_lag_exog is set with load_lag_sources in {"zones", "zone_shares"}, the zone-interim CSV is missing, and config.on_load_lag_failure == "raise".
Examples
With exogenous features disabled the method is a no-op, so the example below runs without any network access and leaves the pipeline target-only.
Delegates to config.forecaster_factory when set; otherwise falls back to default_lgbm_forecaster_factory. This factory hook lets callers swap the estimator without subclassing BaseTask.
Constructs the cross-validation splitter used by all tuning tasks. Internally uses sklearn.model_selection.TimeSeriesSplit to compute split boundaries that respect temporal ordering and avoid data leakage between folds.
The validation boundary is determined by run_state.end_train_ts minus config.delta_val. When config.train_size is set, the sklearn splitter uses a sliding fixed-size training window (max_train_size); otherwise an expanding window is used.
Training time series for the current target. Used both to determine the validation boundary and as the sequence passed to TimeSeriesSplit.split to derive initial_train_size.
Apply hard-bound filtering and IsolationForest outlier detection.
Hard bounds from config.bounds are applied to the pipeline data (out-of-bound values are removed and later filled by impute()). IsolationForest detection (config.use_outlier_detection) is advisory: detected outliers are logged per column but not removed.
Load the most recent fitted models from the cache directory.
Scans <cache_home>/models/<data_frame_name>/ for .joblib files matching the current data_frame_name. Optionally filters by task_name, target, and max_age_days.
Load the most recent tuning results for a target from cache.
Scans <cache_home>/tuning_results/ for files matching the current data_frame_name and target. Optionally filters by task_name and discards results older than max_age_days.
Plotting unavailable in spotforecast2-safe: Plotting is not available in spotforecast2-safe (no plotly/matplotlib). Use the spotforecast2 package for visualisation.
Restrict model loading to a specific source task ("lazy", "defaults", "optuna", or "spotoptim"). None loads the most recent model regardless of source.
Save fitted forecaster models to the cache directory.
Each model is serialised with joblib (compress=3) into <cache_home>/models/<data_frame_name>/ using a datetime-stamped filename so that multiple snapshots can coexist.
If forecasters is None the method collects fitted models from self.results[task_name], where each prediction package is expected to contain a "forecaster" key.
Task identifier ("lazy", "defaults"). The names "optuna" and "spotoptim" are also accepted so that model caches produced by the spotforecast2 sibling package can be saved and loaded; no tuning is performed in this package.