Generate Time Aggregation Expression for Species Data

Creates a SQL-based expression for temporal aggregation of species time series using DuckDB date functions. Used internally by prep_ts_sp.

expr_time_sp(ts_res)

Arguments

ts_res

Character string specifying temporal resolution: "year", "quarter", "month", "day", "year_quarter", "year_month", or "year_day"

Value

Expression object suitable for use in dplyr::mutate() with dbplyr

Details

For seasonal aggregation (ts_res = "quarter"), all quarters are normalized to year 2000 to enable cyclic plotting. Uses DuckDB's date_trunc() and extract() functions for database-side computation.

See also

prep_ts_sp for usage context

Examples

if (FALSE) { # \dontrun{
df_sp |> mutate(time = !!expr_time_sp("year"))
} # }