Convert Old YYMMKK Cruise Key to YYYY-MM-NODC Format — convert_cruise_key

Converts legacy cruise key format (YYMMKK: 2-digit year + 2-digit month + 2-letter ship_key) to the new format (YYYY-MM-NODC: 4-digit year + 2-digit month + NODC ship code). Requires the ship table for KK → NODC mapping.

Usage

convert_cruise_key_format(
  con,
  table,
  old_key_col = "cruise_key",
  ship_tbl = "ship"
)

Arguments

con: DuckDB connection
table: Name of table containing old cruise keys
old_key_col: Name of column with old YYMMKK keys (default: "cruise_key")
ship_tbl: Name of ship table (default: "ship")

Value

Invisibly returns the connection after updating cruise_key column

Details

Century disambiguation: YY >= 49 → 19YY, YY < 49 → 20YY (CalCOFI data spans 1949-present).

Examples

if (FALSE) { # \dontrun{
# convert CTD cruise keys extracted from filenames
convert_cruise_key_format(con, "ctd_cast", "cruise_key_old")
} # }