Re: Special query type for Spatial DB

> If some cells are empty, density can't be uniform. It doesn't matter what
> your space is. Consider 2 dimensional grid of integers:
>
> {(x,y) where x and y are integers}
>
> with distance defined for example as
>
> ||a,b|| = |a_x-b_x|+|a_y-b_y|
>
> then density map of order 5 matches every filled-in node on the grid with
> minimal diameter of a cluster containing a that node plus 4 other
filled-in
> nodes.

All right, this is not entirely true. If only one or couple isolated grid nodes are empty, density defined that way wouldn't really notice. Although, map9 would show diameter 3 on any node which is boundary to empty node, and diameter 2 for all others, whereas map 5 wouldn't be different from the map for totally filled space. Received on Thu Jan 29 2004 - 03:04:48 CET