arch.univariate.FixedVariance.forecast

FixedVariance.forecast(parameters: ArrayLike1D, resids: Float64Array, backcast: Float64Array | float, var_bounds: Float64Array, start: int | None = None, horizon: int = 1, method: ForecastingMethod = 'analytic', simulations: int = 1000, rng: RNGType | None = None, random_state: RandomState | None = None) VarianceForecast

Forecast volatility from the model

Parameters:
parameters: ArrayLike1D

Parameters required to forecast the volatility model

resids: Float64Array

Residuals to use in the recursion

backcast: Float64Array | float

Value to use when initializing the recursion

var_bounds: Float64Array

Array containing columns of lower and upper bounds

start: int | None = None

Index of the first observation to use as the starting point for the forecast. Default is len(resids).

horizon: int = 1

Forecast horizon. Must be 1 or larger. Forecasts are produced for horizons in [1, horizon].

method: ForecastingMethod = 'analytic'

Method to use when producing the forecast. The default is analytic.

simulations: int = 1000

Number of simulations to run when computing the forecast using either simulation or bootstrap.

rng: RNGType | None = None

Callable random number generator required if method is ‘simulation’. Must take a single shape input and return random samples numbers with that shape.

random_state: RandomState | None = None

NumPy RandomState instance to use when method is ‘bootstrap’

Returns:

forecasts – Class containing the variance forecasts, and, if using simulation or bootstrap, the simulated paths.

Return type:

arch.univariate.volatility.VarianceForecast

Raises:

Notes

The analytic method is not supported for all models. Attempting to use this method when not available will raise a ValueError.