Transform an object into a tbl_now

Convert a supported object into a tbl_now. For a plain data.frame / data.table (or an existing tbl_now) you supply the event_date and report_date columns yourself. For objects produced by other packages the conversion is delegated to the matching tbl_now_from_*() converter, which already knows how to map that format – so those methods do not take event_date / report_date.

Usage

as_tbl_now(object, ...)

# S3 method for class 'tbl_now'
as_tbl_now(object, event_date, report_date, ...)

# S3 method for class 'data.frame'
as_tbl_now(object, event_date, report_date, ...)

# S3 method for class 'enw_preprocess_data'
as_tbl_now(object, ...)

# S3 method for class 'reporting_triangle'
as_tbl_now(object, ...)

# S3 method for class 'epidist_linelist_data'
as_tbl_now(object, ...)

# S3 method for class 'epidist_aggregate_data'
as_tbl_now(object, ...)

# S3 method for class 'tbl_ts'
as_tbl_now(object, report_date, event_date = NULL, ...)

# S3 method for class 'data.table'
as_tbl_now(object, event_date, report_date, ...)

# S3 method for class 'tbl_now_epinow2_snapshots'
as_tbl_now(object, ...)

# S3 method for class 'tbl_now_triangle_list'
as_tbl_now(object, ...)

# S3 method for class 'tbl_now_surveillance_list'
as_tbl_now(object, ...)

Arguments

object

An object to convert to a tbl_now.

...

Additional arguments forwarded to the relevant tbl_now_from_*() converter (and therefore to tbl_now()).

event_date, report_date

The event- and report-date columns, as tidy-select expressions – a bare column name or a string both work. Used for data.frame, data.table, tbl_ts (tsibble) and tbl_now inputs; for a tsibble, event_date defaults to the index. They are not arguments of the package-conversion methods (epinowcast, baselinenowcast, epidist), which carry their own date mapping.

Value

A tbl_now object.

Details

Package-specific inputs forward to a dedicated converter. See that converter for the extra arguments it accepts (e.g. strata, max_delay, format, delays_unit, ...), for which columns are carried over, and for the transformation notes / round-trip caveats in its Round-trip section:

• enw_preprocess_data (or a fitted epinowcast object) -> tbl_now_from_epinowcast()

• reporting_triangle (baselinenowcast) -> tbl_now_from_baselinenowcast()

• epidist_linelist_data / epidist_aggregate_data (epidist) -> tbl_now_from_epidist()

• tbl_ts (tsibble) -> tbl_now_from_tsibble()

• data.table -> tbl_now_from_data_table()

Anything passed through ... is forwarded to the underlying converter (and on to tbl_now()), so options such as event_units, now or verbose can be supplied here too.

See also

tbl_now() to build one from scratch; the converters this dispatches to – tbl_now_from_epinowcast(), tbl_now_from_baselinenowcast(), tbl_now_from_epidist(), tbl_now_from_tsibble(), tbl_now_from_data_table() – and the tbl_now_to_*() functions that go the other way. The One dataset, many nowcasts article shows the round trip against each modelling package.

Examples

## For a plain data.frame this is a synonym for tbl_now(): you name the
# columns yourself.
data(denguedat)
as_tbl_now(denguedat, event_date = "onset_week", report_date = "report_week")
#> ℹ Identified data as <linelist-data> where each observation is a test.
#> # A tibble:  52,987 × 6
#> # Data type: "linelist"
#> # Frequency: Event: `weeks` | Report: `weeks`
#>    onset_week   report_week   gender .event_num .report_num .delay
#>    <date>       <date>        <chr>       <dbl>       <dbl>  <dbl>
#>    [event_date] [report_date] [...]       [...]       [...]  [...]
#>  1 1990-01-01   1990-01-01    Male            0           0      0
#>  2 1990-01-01   1990-01-01    Female          0           0      0
#>  3 1990-01-01   1990-01-01    Female          0           0      0
#>  4 1990-01-01   1990-01-08    Female          0           1      1
#>  5 1990-01-01   1990-01-08    Male            0           1      1
#>  6 1990-01-01   1990-01-15    Female          0           2      2
#>  7 1990-01-01   1990-01-15    Female          0           2      2
#>  8 1990-01-01   1990-01-15    Female          0           2      2
#>  9 1990-01-01   1990-01-22    Female          0           3      3
#> 10 1990-01-01   1990-01-08    Female          0           1      1
#> # ────────────────────────────────────────────────────────────────────────────────
#> # Now: 2010-12-20 | Event date: "onset_week" | Report date: "report_week"
#> # ────────────────────────────────────────────────────────────────────────────────
#> # ℹ 52,977 more rows

# For an object built by another nowcasting package you often do not name them,
# because that format already fixes which column is the event date and which
# is the report date. Here we send a tbl_now out to tsibble and bring it back.
if (requireNamespace("tsibble", quietly = TRUE)) {
  ndata <- tbl_now(denguedat,
    event_date = onset_week, report_date = report_week, verbose = FALSE
  )
  ts <- suppressWarnings(tbl_now_to_tsibble(ndata, verbose = FALSE))

  # Bare names and strings both work.
  as_tbl_now(ts, event_date = onset_week, report_date = report_week)
}
#> 
#> ── Converted tsibble <data> into a <tbl_now> 
#> • event_date: "onset_week"
#> • report_date: "report_week"
#> • data_type: "linelist"
#> • now: "2010-12-20"
#> • event_units: "weeks"
#> • report_units: "weeks"
#> • event_date taken from the tsibble index: onset_week
#> # A tibble:  5,154 × 6
#> # Data type: "linelist"
#> # Frequency: Event: `weeks` | Report: `weeks`
#>    onset_week   report_week       n .event_num .report_num .delay
#>    <date>       <date>        <int>      <dbl>       <dbl>  <dbl>
#>    [event_date] [report_date] [...]      [...]       [...]  [...]
#>  1 1990-01-01   1990-01-01        3          0           0      0
#>  2 1990-01-01   1990-01-08       24          0           1      1
#>  3 1990-01-08   1990-01-08        2          1           1      0
#>  4 1990-01-01   1990-01-15       23          0           2      2
#>  5 1990-01-08   1990-01-15       33          1           2      1
#>  6 1990-01-15   1990-01-15        6          2           2      0
#>  7 1990-01-01   1990-01-22        8          0           3      3
#>  8 1990-01-08   1990-01-22        6          1           3      2
#>  9 1990-01-15   1990-01-22       19          2           3      1
#> 10 1990-01-22   1990-01-22        8          3           3      0
#> # ────────────────────────────────────────────────────────────────────────────────
#> # Now: 2010-12-20 | Event date: "onset_week" | Report date: "report_week"
#> # ────────────────────────────────────────────────────────────────────────────────
#> # ℹ 5,144 more rows