Volatility
polars_ts.volatility
GARCH volatility modelling for time series. Closes #51.
GARCHResult
dataclass
Fitted GARCH model result.
garch_fit(df, p=1, q=1, target_col='y', id_col='unique_id', time_col='ds', max_iter=200)
Fit a GARCH(p,q) model to each time series.
Parameters
df Input DataFrame (typically returns or residuals). p Number of lagged squared residuals (ARCH terms). q Number of lagged conditional variances (GARCH terms). target_col Column with the values to model. id_col Column identifying each time series. time_col Column with timestamps. max_iter Maximum optimization iterations.
Returns
dict
Mapping from series ID to :class:GARCHResult.
garch_forecast(model, horizon)
Forecast conditional variance for horizon steps ahead.
Parameters
model
A fitted :class:GARCHResult.
horizon
Number of steps to forecast.
Returns
list[float] Forecast conditional variances.