diseasenowcasting owns the statistical model and RTMB fit;
tbl.now::tbl_nowcast owns the common result grammar. The public result of
nowcast() and auto_nowcast() therefore supports both layers without an
explicit conversion.
Use the native layer for modelling
Use model(), nowcast(), and auto_nowcast() when you need this package's
epidemic, delay, likelihood, revision, or cumulative-process components.
Use fit_check() and nowcast_diagnostic() for RTMB-specific convergence and
fit diagnostics. These functions automatically unwrap the retained native
fit from the common result.
backtest() is a native model-specification convenience, not a second
evaluation system: it translates each model() into a
tbl.now::engine_diseasenowcasting() and returns
tbl.now::nowcast_backtest() directly.
Use the common layer for results and comparison
Use tbl.now::run_nowcast() with
tbl.now::engine_diseasenowcasting() when diseasenowcasting is one of several
engines. Once a fit exists, use the common methods for tidy(), autoplot(),
predictive scoring, forecast conversion, ensembling, and persistence.
In particular, a backtest can be passed directly to
scoringutils::as_forecast_quantile(),
scoringutils::as_forecast_point(), or, when draws were retained,
scoringutils::as_forecast_sample(). Relative WIS and additional scores then
come from scoringutils::score() and
scoringutils::add_relative_skill(), rather than a package-local scorer.
Examples
if (FALSE) { # \dontrun{
fit <- nowcast(data, model = model())
autoplot(fit) # common result plot
fit_check(fit) # native RTMB diagnostics
bt <- backtest(data, models = list(default = model()))
relative <- bt |>
scoringutils::as_forecast_quantile() |>
scoringutils::score() |>
scoringutils::add_relative_skill(metric = "wis")
} # }