Hello, Instead of checking > > return self.polyhedron()._is_positive( self.eval(Vobj) ) > > one should have > > return self.polyhedron()._is_positive( self.eval(Vobj) ) and > not self.polyhedron()._is_zero( self.eval(Vobj) ) >
As Vincent said, this would just be a different kind of wrong. I personally don't mind if you want to turn the old wrong answers into new wrong answers, but perhaps what we should do here is protect the users against a false kind of security. Indeed, anybody who actually plays with RDF matrices directly will soon notice that testing "==0" does not lead very far. What would you think of adding a warning in _is_zero, only when it returns *true* ? If we then write the function your way -- by calling _is_zero -- then we would show a warning whenever some decision is taken based on the output of _is_zero ? This way, all functions that call is_zero would show this warning (only once) on RDF, and ... well, perhaps add to it a suggestion to use an exact ring if results start looking weird ? Nathann -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
