--- a/examples/@polynomial/polynomial.m
+++ b/examples/@polynomial/polynomial.m
@@ -6,23 +6,24 @@
 ## @example
 ## a0 + a1 * x + a2 * x^2 + @dots{} + an * x^n
 ## @end example
+##
+## from a vector of coefficients [a0 a1 a2 ... an].
 ## @end deftypefn
 
 function p = polynomial (a)
   if (nargin == 0)
-    p.poly = [];
+    p.poly = [0];
     p = class (p, "polynomial");
   elseif (nargin == 1)
     if (strcmp (class (a), "polynomial"))
       p = a;
     elseif (isvector (a) && isreal (a))
-      p.poly = a(:)';
+      p.poly = a(:).';
       p = class (p, "polynomial");
     else
-      error ("polynomial: expecting real or complex vector");
+      error ("polynomial: expecting real vector");
     endif
   else
     print_usage ();
   endif
-  superiorto ("double");
 endfunction