Re: level
From: Vadim Tropashko <vadimtro_invalid_at_yahoo.com>
Date: 22 Nov 2003 19:56:53 -0800
Message-ID: <c7ec22df.0311221956.44336486_at_posting.google.com>
Date: 22 Nov 2003 19:56:53 -0800
Message-ID: <c7ec22df.0311221956.44336486_at_posting.google.com>
level = log(1 - y/x)
or, equivalently,
level = log(1-lft/rgt)
Note, that Celko Nested Sets model have nice agregated formula for descendants
number_of_descendants = (rgt-lft+1)/2
while don't have any formula for the level. In binary rational nested intervals encoding the situation is completely reverse: there couldn't be any identity for descendants, because tree is allowed to grow without changing node labels. Received on Sun Nov 23 2003 - 04:56:53 CET