Changes in version 0.2.0.9000 Changes in version 0.2.0 (2026-01-31) Fast Additive Switching of Seasonality, Trend and Exogenous Regressors (FASSTER) is a state space model designed for forecasting time series with multiple seasonal patterns. The model extends traditional state space models by introducing a switching component to the measurement equation, enabling flexible modeling of complex seasonal patterns, and time series dynamics with rapid structural changes. - FASSTER model implementation: - Model specification: Flexible formula interface supporting: - trend() for polynomial trends - season() for seasonal factors - fourier() for trigonometric seasonal terms - ARMA() for autoregressive moving average components - xreg() for exogenous regressors - %S% switching operator for group-specific model structures - %?% conditional operator for time-varying components - Model methods: Full integration with the fable framework: - fitted() and residuals() for model diagnostics - augment() for augmenting data with model estimates - tidy() for extracting coefficients (initial state estimates) - glance() for model summary statistics (AIC, BIC, log-likelihood) - report() for displaying estimated state and observation variances - components() for decomposing fitted values into trend and seasonal components - forecast() for generating predictions - interpolate() for filling missing values - refit() for applying a fitted model to new data with optional re-estimation - stream() for extending models with new observations - Heuristic estimation: Model parameters are estimated using a heuristic approach based on filtering and smoothing to obtain initial state parameters and variance estimates.