[
https://issues.apache.org/jira/browse/LUCENE-6450?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14538052#comment-14538052
]
Karl Wright commented on LUCENE-6450:
-------------------------------------
A word of caution. For polygons, most cartographers would not consider the
following to accurately represent a polygon on a sphere:
{code}
+ public static boolean pointInPolygon(double[] x, double[] y, double lat,
double lon) {
+ assert x.length == y.length;
+ boolean inPoly = false;
+
+ for (int i = 1; i < x.length; i++) {
+ if (x[i] < lon && x[i-1] >= lon || x[i-1] < lon && x[i] >= lon) {
+ if (y[i] + (lon - x[i]) / (x[i-1] - x[i]) * (y[i-1] - y[i]) <
lat) {
+ inPoly = !inPoly;
+ }
+ }
+ }
+ return inPoly;
+ }
{code}
This is a cartesian approximation only -- polygon edges would appear to be
curved on a globe. This will limit usage to applications for which cartesian
approximations are acceptable.
> Add simple encoded GeoPointField type to core
> ---------------------------------------------
>
> Key: LUCENE-6450
> URL: https://issues.apache.org/jira/browse/LUCENE-6450
> Project: Lucene - Core
> Issue Type: New Feature
> Affects Versions: Trunk, 5.x
> Reporter: Nicholas Knize
> Priority: Minor
> Attachments: LUCENE-6450-5x.patch, LUCENE-6450-TRUNK.patch,
> LUCENE-6450.patch, LUCENE-6450.patch, LUCENE-6450.patch, LUCENE-6450.patch
>
>
> At the moment all spatial capabilities, including basic point based indexing
> and querying, require the lucene-spatial module. The spatial module, designed
> to handle all things geo, requires dependency overhead (s4j, jts) to provide
> spatial rigor for even the most simplistic spatial search use-cases (e.g.,
> lat/lon bounding box, point in poly, distance search). This feature trims the
> overhead by adding a new GeoPointField type to core along with
> GeoBoundingBoxQuery and GeoPolygonQuery classes to the .search package. This
> field is intended as a straightforward lightweight type for the most basic
> geo point use-cases without the overhead.
> The field uses simple bit twiddling operations (currently morton hashing) to
> encode lat/lon into a single long term. The queries leverage simple
> multi-phase filtering that starts by leveraging NumericRangeQuery to reduce
> candidate terms deferring the more expensive mathematics to the smaller
> candidate sets.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
