(Btw sorry if this is off-topic, but Nemo, thank you a lot in your post for at least making it clear you are curious what he wants to do. In the past on other calc forums, especially MaxCoderz, when someone asked a question where he is doing something new or close, he often got told "Why do you want to do that?" as sole response, as if he was not allowed to do anything unconventional. Way to allow the community to innovate. At least you did not do that and I appreciate it and gave you +1 for this post. Other people elsewhere should follow example.)