Function interp_outer 

fn interp_outer(
    positional: &[RValue],
    named: &[(String, RValue)],
    context: &BuiltinContext<'_>,
) -> Result<RValue, RError>

Outer product of two vectors, applying FUN to each pair of elements.

@param X first vector @param Y second vector @param FUN function to apply (default: “*”) @return matrix with dim = c(length(X), length(Y))