Coerce a tbl_nowcast into a tibble

Turns a fitted nowcast into an ordinary tibble you can plot, join or write out: one row per event date and quantile level by default, or one row per posterior draw with type = "draws".

Not every engine keeps draws. When the backend returned only summarised quantiles, type = "draws" has nothing to give you.

Arguments

x

A tbl_nowcast.

...

Unused.

type

Either "quantiles" (default) for the tidy quantile predictions, or "draws" for the posterior draws.

Value

A tibble. For type = "quantiles", one row per event date, stratum and quantile level, with the quantile level in .quantile_level and the predicted count in .value. For type = "draws", one row per draw.

Details

Registered in .onLoad() rather than assigned with S7::method(as_tibble, tbl_nowcast) <- , which is what the neighbouring print() and as.data.frame() methods use. Assigning an S7 method onto an imported generic copies that generic into this namespace, and tibble::as_tibble() carries rownames = pkgconfig::get_config(...) as a default argument – so the copy makes R CMD check report pkgconfig as an undeclared :: import of a package this one never uses. Plain S3 registration dispatches on class(x), which for an S7 object is "tbl.now::tbl_nowcast", and copies nothing.

See also

tidy() for the same content with the engine's metadata attached; autoplot() to plot it; score_nowcast() to score it against observed counts.

Examples

predictions <- data.frame(
  onset_week = as.Date("2020-01-05"),
  .quantile_level = c(0.5, 0.9), .value = c(10, 14)
)
nc <- tbl_nowcast(predictions = predictions, method = "toy", event_date = "onset_week")
tibble::as_tibble(nc)
#> # A tibble: 2 × 3
#>   onset_week .quantile_level .value
#>   <date>               <dbl>  <dbl>
#> 1 2020-01-05             0.5     10
#> 2 2020-01-05             0.9     14