Function builtin_ordered 

fn builtin_ordered(
    args: &[RValue],
    named: &[(String, RValue)],
) -> Result<RValue, RError>

Construct an ordered factor.

Delegates to factor() with ordered = TRUE. Ordered factors represent ordinal data where the levels have a meaningful order.

@param x vector to encode (default: character()) @param levels character vector of allowed levels (default: sorted unique values) @param labels character vector of display labels for the levels @return an ordered factor (integer vector with “levels” and “class” attributes)