lucene-general mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "patrick o'leary" <>
Subject Re: [spatial] Cartesian "Tiers" nomenclature
Date Tue, 29 Dec 2009 21:10:51 GMT
Must try and get back to work some time today.. So let me keep this brief

> If a "single cartesian tier" is "of limited use", why do you have a class
> called "CartesianTier" at all?
A bit is useless on it's own- A collection of bits allows you to do
something. Why not a CartesianSet ?
Because lucene is the set holder - That is the point of the index
In fact there isn't a CartesianTier class, there is a CartesianTierPlotter
class that returns a double as the coordinate from a getBoxId method.
This allows it to be used outside of lucene if wanted. And in fact several
folks do use it outside of lucene.

> I would like to minimize the effort it takes to learn your tool.  Good
> class
> names make that easier.

There are 3 simple parts to this
1) Something to plot latitudes / longitudes based on a projection
   -- CartesianTierPlotter

2) A projection method (standard GIS terminology)
  -- IProjector

3) A way to search it
 -- For lucene this is the DistanceQueryBuilder

I can't see how it's much simpler, if you don't want to dig into GIS, then
it's all there neatly wrapped up.

On Tue, Dec 29, 2009 at 12:29 PM, Marvin Humphrey <>wrote:

> patrick o'leary:
> > CartesianTier's adequately describes what the design does- Layer one
> > cartesian coordinate system on top of another....
> So CartesianTier objects actually represent *multiple* tiers?
> Would "CartesianTierSet" be more accurate, albeit cumbersome?  I'm not
> suggesting that as an alternative, I'm just trying to understand what the
> class does.
> Obviously I can go browse the JavaDocs and read the source code, and I will
> eventually.  In Lucyland, we've adopted a tradition of recording
> "brainlogs"
> while browsing unfamiliar documentation as a form of UI testing -- I'll do
> one
> of those later.  For the moment, though, I'm your trainee test case.  Use
> the
> places where I'm confused to help you refine your API.  (; Or to confirm to
> yourself that it is perfect already. ;)
> > It's not a grid system, grids describe the bounding lines - where a point
> is
> > x,y : x1,y1, the intersection of 2 grid lines.
> I don't fully understand what you mean, but I think I disagree.  It's
> common
> to overlay two "grids" of differing resolutions on top of each other.  So
> if a
> "tier" is a zoom level, it seems to me that the word "grid" conveys that
> same
> concept pretty well.
> > Cartesian Tiles ? again a web mapping concept ... that's dropping the
> > concept of tiers.
> Yes, I think the word "tile" suggests a single rectangular cell.  But it's
> common to rasterize a surface into multiple tile sets at different zoom
> levels and then search on tiles as terms.
> Coming at this from a "web guy" perspective, I figured we were talking
> about
> something like that -- and *not* bounding boxes a la R-trees.
> > A single cartesian tier on it's own is of limited use.
> Interesting.  I guess a zoom level without any geographical data isn't
> useful,
> but it still seems like something important that could be encapsulated
> within
> an object.  In fact that's exactly what the name "CartesianTier" seemed to
> suggest, since it's singular.
> If a "single cartesian tier" is "of limited use", why do you have a class
> called "CartesianTier" at all?
> > What effort do you have down the road, and how does the name of it create
> > problems for you?
> I have to learn how to use your tool, obviously.  Presumably you want me to
> use your tool, too, or you wouldn't have published it.
> I would like to minimize the effort it takes to learn your tool.  Good
> class
> names make that easier.
> > If I were calling this PatrickGeoSolutions or MagicalGeoStuff then I
> would
> > understand the problem, What I'm doing is calling it by what it's doing
> > generating a Cartesian Tiered system
> All these messages have gone by and I *still* don't understand what a
> CartesianTier is.  I'm artificially preserving my ignorance by avoiding the
> JavaDocs and source code, but IMO, I ought to have grokked that by now.  Or
> you can blame the user...
> > But is that really worth breaking all the existing references to this?
> What
> > value is that for the users?
> Breaking all the references is obviously a negative.  You only do such a
> thing
> when the gains outweigh the costs.
> Marvin Humphrey

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message