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Posted to dev@lucene.apache.org by "Karl Wright (JIRA)" <ji...@apache.org> on 2015/02/02 07:57:34 UTC
[jira] [Comment Edited] (LUCENE-6196) Include geo3d package, along
with Lucene integration to make it useful
[ https://issues.apache.org/jira/browse/LUCENE-6196?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14300944#comment-14300944 ]
Karl Wright edited comment on LUCENE-6196 at 2/2/15 6:56 AM:
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bq. There's one thing I want to confirm with you Karl: so these shares are "accurate" to the spherical model (the unit sphere)? That is, if I have say a line string, then is each line segment a great-circle path between its start & end? If not then can you please explain?
In part this depends on the shape. For GeoConvexPolygons, the surface paths are all great circles. For GeoCircles, it's a circle not a great circle. For GeoPaths, the boundary of the shape consists of a zone of a specific width on either side of a great circle, so the boundary is not (if you think about it) actually a great circle. For GeoBBox shapes (e.g. GeoRectangles), they are great circles in longitude, but horizontal slices in latitude. This matches the standard "rectangle" metaphor that quad trees are built on.
was (Author: kwright@metacarta.com):
bq: There's one thing I want to confirm with you Karl: so these shares are "accurate" to the spherical model (the unit sphere)? That is, if I have say a line string, then is each line segment a great-circle path between its start & end? If not then can you please explain?
In part this depends on the shape. For GeoConvexPolygons, the surface paths are all great circles. For GeoCircles, it's a circle not a great circle. For GeoPaths, the boundary of the shape consists of a zone of a specific width on either side of a great circle, so the boundary is not (if you think about it) actually a great circle. For GeoBBox shapes (e.g. GeoRectangles), they are great circles in longitude, but horizontal slices in latitude. This matches the standard "rectangle" metaphor that quad trees are built on.
> Include geo3d package, along with Lucene integration to make it useful
> ----------------------------------------------------------------------
>
> Key: LUCENE-6196
> URL: https://issues.apache.org/jira/browse/LUCENE-6196
> Project: Lucene - Core
> Issue Type: New Feature
> Components: modules/spatial
> Reporter: Karl Wright
> Assignee: David Smiley
> Attachments: ShapeImpl.java, geo3d-tests.zip, geo3d.zip
>
>
> I would like to explore contributing a geo3d package to Lucene. This can be used in conjunction with Lucene search, both for generating geohashes (via spatial4j) for complex geographic shapes, as well as limiting results resulting from those queries to those results within the exact shape in highly performant ways.
> The package uses 3d planar geometry to do its magic, which basically limits computation necessary to determine membership (once a shape has been initialized, of course) to only multiplications and additions, which makes it feasible to construct a performant BoostSource-based filter for geographic shapes. The math is somewhat more involved when generating geohashes, but is still more than fast enough to do a good job.
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