Marvin, then by all means write your own sir
On Tue, Dec 29, 2009 at 4:13 PM, Marvin Humphrey <mar...@rectangular.com>wrote: > On Tue, Dec 29, 2009 at 03:55:22PM -0800, Marvin Humphrey wrote: > > > I'll save conclusion #2 for a separate email. > > Conclusion # 2 > ============== > > The concepts used in spatial contrib are easy -- much easier than I'd come > to > assume, given how drawn out this conversation has gotten. (Projections are > hard, but I already grok them, and they play a minor role.) In fact, > spatial > contrib works almost exactly like I would have expected. Some places I've > worked have implemented almost exactly the same algorithms independently. > > I continue to disagree with Patrick about elevating the word "tier". There > doesn't seem to be anything special about it. In fact, the "tiers" in > spatial > contrib refer to zoom levels which are always powers of two... > > tier 0: 1x1 = 1 tile > tier 1: 2x2 = 4 tiles > tier 2: 4x4 = 16 tiles > ... > > ... but for this algorithm, different rasterization resolutions need not > proceed by powers-of-two. IMO CartesianGrid is better, as it encapsulates > the > same data using more popular terminology. You could also say that a > CartesianGrid has a resolution zoom level, and that in this implementation > it's tied to a power-of-two "tier". However, assigning such a meaning to > the > word "tier" is arbitrary. > > I might even suggest ZoomLevel as an alternative to CartesianTier, and > bounce > the term "Rasterization" out there for kicks. > > On the other hand, "Cartesian Tile" would not be appropriate at all as a > substitute for "Cartesian Tier". My sense is that "tile", "box", and > "cell" > are all basically the same and refer to a single rectangle, while > Tier/Grid/ZoomLevel/etc. are composites encapsulating multiple > tiles/boxes/cells. > > Marvin Humphrey > >
