Enumerate every instant in a year mapped to its calendar slice

Returns a data.frame with one row per instant in the requested year at the requested resolution, plus a slice column giving the calendar slice that instant belongs to (via instant_to_slice()). This is the ground truth used by recast().

Usage

expand_calendar(calendar, year, by = NULL, tz = "UTC")

Arguments

calendar: A Calendar.
year: Integer scalar — the Gregorian year to enumerate.
by: Resolution string passed to seq.POSIXt's by argument ("hour", "day", "15 min", ...). Defaults to "hour" if HOUR is in the calendar's timeframes, otherwise "day".
tz: Time zone string. Defaults to "UTC".

Value

A data.frame with columns datetime (POSIXct) and slice (character). Rows where slice is NA correspond to instants the calendar does not cover (e.g. Feb 29 in a 365-day calendar).

Examples

df <- data.frame(
  MONTH  = sprintf("m%02d", 1:12),
  share  = c(31,28,31,30,31,30,31,31,30,31,30,31) / 365,
  weight = c(31,28,31,30,31,30,31,31,30,31,30,31)
)
cal <- calendar_from_leaves(df, timeframes = "MONTH", name = "m12")
grid <- expand_calendar(cal, year = 2021, by = "month")
head(grid)
#>     datetime slice
#> 1 2021-01-01   m01
#> 2 2021-02-01   m02
#> 3 2021-03-01   m03
#> 4 2021-04-01   m04
#> 5 2021-05-01   m05
#> 6 2021-06-01   m06