Extract metadata from raw data

Extract metadata from raw data, either by reference or by report date. For the target date chosen (reference or report), confirm, max_confirm``, and cum_prop_reported` are dropped and the first observation for each group and date is retained.

Usage

enw_metadata(obs, target_date = c("reference_date", "report_date"))

Arguments

obs

A data.frame or data.table with columns: reference_date and / or report_date; at least one must be provided, .group, a grouping column and a date, a Date column.

target_date

A character string, either "reference_date" or "report_date". The column corresponding to this string will be used as the target date for metadata extraction.

Value

A data.table with columns:

• date, a Date column

• .group, a grouping column

and the first observation for each group and date. The data.table is sorted by .group and date.

See also

Preprocessing functions enw_add_delay(), enw_add_max_reported(), enw_add_metaobs_features(), enw_assign_group(), enw_complete_dates(), enw_construct_data(), enw_extend_date(), enw_filter_delay(), enw_filter_reference_dates(), enw_filter_report_dates(), enw_flag_observed_observations(), enw_impute_na_observations(), enw_latest_data(), enw_metadata_delay(), enw_missing_reference(), enw_preprocess_data(), enw_reporting_triangle_to_long(), enw_reporting_triangle()

Examples

obs <- data.frame(
  reference_date = as.Date("2021-01-01"),
  report_date = as.Date("2022-01-01"), x = 1:10
)
enw_metadata(obs, target_date = "reference_date")
#> Key: <.group, date>
#>          date .group     x
#>        <Date>  <num> <int>
#> 1: 2021-01-01      1     1