%g2o = ( 128 => 'a',
         13 => 'b',
         34 => 'a',
         28 => 'c' );
@allgs = (128, 13, 34 );
@allgsplane = sort { ($g2o{$a} cmp $g2o{$b}) || ($a <=> $b) } @allgs;
print "@allgsplane\n";

##</code><code>##

34 128 13