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Cameron Mace
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Adds nearest turf function
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Lines changed: 226 additions & 1 deletion

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‎docs/turf-port.md‎

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@@ -104,7 +104,7 @@ The helper functions are all part of the GeoJson module; this class contains uni
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- [ ] turf-triangle-grid
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## Classification
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- [ ] turf-nearest
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- [x] turf-nearest
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## Aggregation
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- [ ] turf-collect

‎services-turf/src/main/java/com/mapbox/turf/TurfClassification.java‎

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package com.mapbox.turf;
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import android.support.annotation.NonNull;
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import com.mapbox.geojson.Point;
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import java.util.List;
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/**
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* Methods found in this class are meant to consume a set of information and classify it according
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* to a shared quality or characteristic.
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*
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* @since 3.0.0
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*/
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public class TurfClassification {
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/**
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* Takes a reference point and a list of {@link Point} geometries and returns the point from the
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* set point list closest to the reference. This calculation is geodesic.
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*
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* @param targetPoint the reference point
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* @param points set list of points to run against the input point
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* @return the closest point in the set to the reference point
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* @since 3.0.0
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*/
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@NonNull
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public static Point nearest(@NonNull Point targetPoint, @NonNull List<Point> points) {
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if (points.isEmpty()) {
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return targetPoint;
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}
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Point nearestPoint = points.get(0);
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double minDist = Double.POSITIVE_INFINITY;
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for (Point point : points) {
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double distanceToPoint = TurfMeasurement.distance(targetPoint, point);
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if (distanceToPoint < minDist) {
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nearestPoint = point;
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minDist = distanceToPoint;
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}
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}
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return nearestPoint;
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}
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}

‎services-turf/src/test/java/com/mapbox/turf/TurfClassificationTest.java‎

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package com.mapbox.turf;
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import com.mapbox.geojson.Feature;
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import com.mapbox.geojson.FeatureCollection;
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import com.mapbox.geojson.Point;
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import com.mapbox.services.TestUtils;
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import org.junit.Assert;
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import org.junit.Test;
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import java.io.IOException;
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import java.util.ArrayList;
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import java.util.List;
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public class TurfClassificationTest extends TestUtils {
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private static final String PT = "turf-classification/pt.json";
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private static final String PTS = "turf-classification/pts.json";
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@Test
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public void testLineDistanceWithGeometries() throws IOException, TurfException {
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Point pt = (Point) Feature.fromJson(loadJsonFixture(PT)).geometry();
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FeatureCollection pts = FeatureCollection.fromJson(loadJsonFixture(PTS));
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List<Point> pointList = new ArrayList<>();
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for (Feature feature : pts.features()) {
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pointList.add((Point) (feature.geometry()));
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}
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Point closestPt = TurfClassification.nearest(pt, pointList);
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Assert.assertNotNull(closestPt);
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Assert.assertEquals(closestPt.type(), "Point");
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Assert.assertEquals(closestPt.longitude(), -75.33, DELTA);
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Assert.assertEquals(closestPt.latitude(), 39.44, DELTA);
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}
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}

‎services-turf/src/test/resources/turf-classification/pt.json‎

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{
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"type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.4, 39.4]},
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"properties": {
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"name": "Location A",
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"category": "Store"
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}
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}

‎services-turf/src/test/resources/turf-classification/pts.json‎

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{
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"type": "FeatureCollection",
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"features": [
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.833, 39.284]},
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"properties": {
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"name": "Location B",
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"category": "House",
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"elevation": 25
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.6, 39.984]},
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"properties": {
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"name": "Location A",
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"category": "Store",
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"elevation": 23
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.221, 39.125]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 29
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.358, 39.987]},
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"properties": {
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"name": "Location A",
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"category": "Store",
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"elevation": 12
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.9221, 39.27]},
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"properties": {
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"name": "Location B",
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"category": "House",
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"elevation": 11
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.534, 39.123]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 49
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.21, 39.12]},
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"properties": {
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"name": "Location A",
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"category": "Store",
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"elevation": 50
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.22, 39.33]},
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"properties": {
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"name": "Location B",
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"category": "House",
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"elevation": 90
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.44, 39.55]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 22
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.77, 39.66]},
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"properties": {
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"name": "Location A",
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"category": "Store",
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"elevation": 99
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.44, 39.11]},
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"properties": {
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"name": "Location B",
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"category": "House",
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"elevation": 55
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.05, 39.92]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 41
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.88, 39.98]},
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"properties": {
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"name": "Location A",
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"category": "Store",
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"elevation": 52
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [-75.55, 39.55]},
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"properties": {
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"name": "Location B",
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"category": "House",
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"elevation": 143
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.33, 39.44]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 76
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.56, 39.24]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 18
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}
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},
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{ "type": "Feature",
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"geometry": {"type": "Point", "coordinates": [ -75.56, 39.36]},
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"properties": {
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"name": "Location C",
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"category": "Office",
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"elevation": 52
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}
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}
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]
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}

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