Select of a function that returns a array

Hi guys

I'm trying to figure out a way to make this select work even for a wrong value:

select mean_and_variancepop('golf', 'temperature');
or
select CAST (mean_and_variancepop('golf', 'temperature') AS float(2));

This function return an array

the function is:

CREATE or replace FUNCTION mean_and_variancepop(var_table varchar,
var_col varchar) RETURNS float(2) AS $$
DECLARE  curs refcursor;  a float;  b float;  c float;  retvals float[2];  sum float:=0;
BEGIN  open curs FOR EXECUTE 'SELECT ' || quote_ident(var_col) || ' FROM
' || quote_ident(var_table);  b:=0;

LOOP -- some computations
FETCH curs INTO a;
  IF  NOT FOUND THEN      EXIT;  -- exit loop  END IF;  b:=b+1;  c:=a;  sum:= sum + c;
END LOOP;  CLOSE curs;  retvals[0]:= sum / b;  retvals[1] :=4;  RETURN retvals;

END;
$$ LANGUAGE plpgsql;

Thanks
-Jr