Markiyan Hirnyk, thank you very, very much! That's a really elegant way to solve my problem. 

Markiyan Hirnyk, thank you very, very much! That's a really elegant way to solve my problem. 

Thank you, it works. But the point plot doesn't look like my initial implicit plot. It looks like the one in the Markiyan Hirnyk's message.

Thank you, it works. But the point plot doesn't look like my initial implicit plot. It looks like the one in the Markiyan Hirnyk's message.