Convert Race to Numeric Code
Details
Default mapping: White = 1, Black = 2, Asian = 3, American Native = 4,
Pacific Islander = 5, Other = 6. "UNKNOWN" and NA map to the missing
value indicator (getOption("scicalc.missing_value", -999)). Any other
value is treated as unspecified: it maps to NA and triggers a warning.
The scicalc.racen_config option (a named numeric vector) customizes the
mapping. A name matching a built-in category ("white", "black",
"asian", "american native", "pacific islander", "other") overrides
that category's code (synonyms included). Any other name adds a new
exact-match category. For example
options(scicalc.racen_config = c("WHITE" = 2, "JAPANESE" = 7)).
