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Karl Wright commented on LUCENE-6196: ------------------------------------- Unless I made a math error, I get the following for longitude bounds: {code} ADx0 + BDy0 - C^2 = 0 {code} ... combined with either: {code} [C^2 * D^2 * (B^2 + A^2)] * y0^2 + [-2*C^4*BD] * y0 + [C^6 + A^2 * C^4 + A^2 * D^2 * C^2] = 0 x0 = (-BDy0 + C^2) / AD {code} ... or its counterpart, solving for x0: {code} [C^2 * D^2 * (B^2 + A^2)] * x0^2 + [-2*C^4*BD] * x0 + [C^6 + B^2 * C^4 + B^2 * D^2 * C^2] = 0 y0 = (-ADx0 + C^2) / BD {code} Either way, the minimum or maximum longitude, provided there are any solutions (x0,y0), is given by: {code} longitude = atan(y0/x0) {code} So as soon as I confirm this math, I can implement a general bounds solution for an arbitrary plane intersecting the unit sphere, which should allow me to provide bounding boxes for all shapes built on 3d bounding planes. > 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.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. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org