Thanks for the help you’ve already given me on getting search with LatLonPoint working, the basics are working great and with great performance.
I did some testing on some edge cases and discovered that indexing and searching for points at the minimum and maximum latitude and longitude are not working as I expected. I’d appreciate some feedback on this. Take for example the point (0.0, 180.0) which is in the Pacific ocean at latitude = 0.0 and longitude = 180.0. If we create a grid of 9 points centered on this location (“tic tac toe” layout) with an offset of 0.1 the coordinates would be: (0.1, -179.9), (0.0, -179.9), (-0.1, -179.9), (0.1, 180.0), (0.0, 180.0), (-0.1, 180.0), (0.1, 179.9), (0.0, 179.9), (-0.1, 179.9) The max longitude is 180, so if you move 0.1 degree east the next longitude is actually -179.9 rather than 180.1, it wraps around. If I then create a square that encompasses these points using an offset of 1.0 (larger than the 0.1 for the indexed points) that polygon would have these endpoints: (-1.0, 179.0}, (1.0, 179.0), (1.0, -179.0), (-1.0, -179.0), (-1.0, 179.0) The first and last point are the same so that this is a closed polygon. When I index these points with LatLonPoint and do a search with LatLonPoint.newPolygonQuery() it does not return any results, which isn’t what I expected. However, if I index a grid of points around (0.0, 0.0) and search with this polygon, they are returned by this search, which I don’t believe is correct. It is as if the search thinks that the point (0.0, 0.0) is between the points (0.0, 179) and (0.0, -179) which I don’t think is correct. Longitude 0.0 and 180.0 are on opposite sides of the globe. I see the same behavior with data centered at these points: (90.0, -180.0) (90.0, 0.0) (90.0, 180.0) (0.0, -180.0) (0.0, 180.0) (-90.0, -180.0) (-90.0, 0.0) (-90.0, 180.0) However, using more “normal” points such as (44.4605, -110.8281) this test works fine. So I’m wondering if there is a problem with the search handling polygons that span the latitude and longitude boundaries, or if maybe I am just not thinking about this right to begin with. I can post sample code if that would be helpful. Thanks for any assistance / input. Randy --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
