--- a/scripts/general/triu.m
+++ b/scripts/general/triu.m
@@ -47,3 +47,23 @@
   endfor
 
 endfunction
+
+%!test
+%! a = [1, 2, 3; 4, 5, 6; 7, 8, 9; 10, 11, 12];
+%! 
+%! u0 = [1, 2, 3; 0, 5, 6; 0, 0, 9; 0, 0, 0];
+%! u1 = [0, 2, 3; 0, 0, 6; 0, 0, 0; 0, 0, 0];
+%! u2 = [0, 0, 3; 0, 0, 0; 0, 0, 0; 0, 0, 0];
+%! u3 = [0, 0, 0; 0, 0, 0; 0, 0, 0; 0, 0, 0];
+%! um1 = [1, 2, 3; 4, 5, 6; 0, 8, 9; 0, 0, 12];
+%! um2 = [1, 2, 3; 4, 5, 6; 7, 8, 9; 0, 11, 12];
+%! um3 = [1, 2, 3; 4, 5, 6; 7, 8, 9; 10, 11, 12];
+%! 
+%! assert((triu (a, -3) == um3 && triu (a, -2) == um2
+%! && triu (a, -1) == um1 && triu (a) == u0 && triu (a, 1) == u1
+%! && triu (a, 2) == u2 && triu (a, 3) == u3));
+
+%!error triu ();
+
+%!error triu (1, 2, 3);
+