package org.apache.lucene.demo.facet;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.Closeable;
import java.io.IOException;
import java.text.ParseException;
import org.apache.lucene.analysis.core.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.DoubleField;
import org.apache.lucene.document.Field;
import org.apache.lucene.expressions.Expression;
import org.apache.lucene.expressions.SimpleBindings;
import org.apache.lucene.expressions.js.JavascriptCompiler;
import org.apache.lucene.facet.DrillDownQuery;
import org.apache.lucene.facet.DrillSideways;
import org.apache.lucene.facet.FacetResult;
import org.apache.lucene.facet.Facets;
import org.apache.lucene.facet.FacetsCollector;
import org.apache.lucene.facet.FacetsConfig;
import org.apache.lucene.facet.range.DoubleRange;
import org.apache.lucene.facet.range.DoubleRangeFacetCounts;
import org.apache.lucene.facet.taxonomy.TaxonomyReader;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.queries.BooleanFilter;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.search.BooleanClause;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.NumericRangeFilter;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.SloppyMath;
/** Shows simple usage of dynamic range faceting, using the
* expressions module to calculate distance. */
public class DistanceFacetsExample implements Closeable {
final DoubleRange ONE_KM = new DoubleRange("< 1 km", 0.0, true, 1.0, false);
final DoubleRange TWO_KM = new DoubleRange("< 2 km", 0.0, true, 2.0, false);
final DoubleRange FIVE_KM = new DoubleRange("< 5 km", 0.0, true, 5.0, false);
final DoubleRange TEN_KM = new DoubleRange("< 10 km", 0.0, true, 10.0, false);
private final Directory indexDir = new RAMDirectory();
private IndexSearcher searcher;
private final FacetsConfig config = new FacetsConfig();
/** The "home" latitude. */
public final static double ORIGIN_LATITUDE = 40.7143528;
/** The "home" longitude. */
public final static double ORIGIN_LONGITUDE = -74.0059731;
/** Radius of the Earth in KM
*
* NOTE: this is approximate, because the earth is a bit
* wider at the equator than the poles. See
* http://en.wikipedia.org/wiki/Earth_radius */
public final static double EARTH_RADIUS_KM = 6371.01;
/** Empty constructor */
public DistanceFacetsExample() {}
/** Build the example index. */
public void index() throws IOException {
IndexWriter writer = new IndexWriter(indexDir, new IndexWriterConfig(FacetExamples.EXAMPLES_VER,
new WhitespaceAnalyzer(FacetExamples.EXAMPLES_VER)));
// TODO: we could index in radians instead ... saves all the conversions in getBoundingBoxFilter
// Add documents with latitude/longitude location:
Document doc = new Document();
doc.add(new DoubleField("latitude", 40.759011, Field.Store.NO));
doc.add(new DoubleField("longitude", -73.9844722, Field.Store.NO));
writer.addDocument(doc);
doc = new Document();
doc.add(new DoubleField("latitude", 40.718266, Field.Store.NO));
doc.add(new DoubleField("longitude", -74.007819, Field.Store.NO));
writer.addDocument(doc);
doc = new Document();
doc.add(new DoubleField("latitude", 40.7051157, Field.Store.NO));
doc.add(new DoubleField("longitude", -74.0088305, Field.Store.NO));
writer.addDocument(doc);
// Open near-real-time searcher
searcher = new IndexSearcher(DirectoryReader.open(writer, true));
writer.close();
}
private ValueSource getDistanceValueSource() {
Expression distance;
try {
distance = JavascriptCompiler.compile(
"haversin(" + ORIGIN_LATITUDE + "," + ORIGIN_LONGITUDE + ",latitude,longitude)");
} catch (ParseException pe) {
// Should not happen
throw new RuntimeException(pe);
}
SimpleBindings bindings = new SimpleBindings();
bindings.add(new SortField("latitude", SortField.Type.DOUBLE));
bindings.add(new SortField("longitude", SortField.Type.DOUBLE));
return distance.getValueSource(bindings);
}
/** Given a latitude and longitude (in degrees) and the
* maximum great circle (surface of the earth) distance,
* returns a simple Filter bounding box to "fast match"
* candidates. */
public static Filter getBoundingBoxFilter(double originLat, double originLng, double maxDistanceKM) {
// Basic bounding box geo math from
// http://JanMatuschek.de/LatitudeLongitudeBoundingCoordinates,
// licensed under creative commons 3.0:
// http://creativecommons.org/licenses/by/3.0
// TODO: maybe switch to recursive prefix tree instead
// (in lucene/spatial)? It should be more efficient
// since it's a 2D trie...
// Degrees -> Radians:
double originLatRadians = Math.toRadians(originLat);
double originLngRadians = Math.toRadians(originLng);
double angle = maxDistanceKM / (SloppyMath.earthDiameter(originLat) / 2.0);
double minLat = originLatRadians - angle;
double maxLat = originLatRadians + angle;
double minLng;
double maxLng;
if (minLat > Math.toRadians(-90) && maxLat < Math.toRadians(90)) {
double delta = Math.asin(Math.sin(angle)/Math.cos(originLatRadians));
minLng = originLngRadians - delta;
if (minLng < Math.toRadians(-180)) {
minLng += 2 * Math.PI;
}
maxLng = originLngRadians + delta;
if (maxLng > Math.toRadians(180)) {
maxLng -= 2 * Math.PI;
}
} else {
// The query includes a pole!
minLat = Math.max(minLat, Math.toRadians(-90));
maxLat = Math.min(maxLat, Math.toRadians(90));
minLng = Math.toRadians(-180);
maxLng = Math.toRadians(180);
}
BooleanFilter f = new BooleanFilter();
// Add latitude range filter:
f.add(NumericRangeFilter.newDoubleRange("latitude", Math.toDegrees(minLat), Math.toDegrees(maxLat), true, true),
BooleanClause.Occur.MUST);
// Add longitude range filter:
if (minLng > maxLng) {
// The bounding box crosses the international date
// line:
BooleanFilter lonF = new BooleanFilter();
lonF.add(NumericRangeFilter.newDoubleRange("longitude", Math.toDegrees(minLng), null, true, true),
BooleanClause.Occur.SHOULD);
lonF.add(NumericRangeFilter.newDoubleRange("longitude", null, Math.toDegrees(maxLng), true, true),
BooleanClause.Occur.SHOULD);
f.add(lonF, BooleanClause.Occur.MUST);
} else {
f.add(NumericRangeFilter.newDoubleRange("longitude", Math.toDegrees(minLng), Math.toDegrees(maxLng), true, true),
BooleanClause.Occur.MUST);
}
return f;
}
/** User runs a query and counts facets. */
public FacetResult search() throws IOException {
FacetsCollector fc = new FacetsCollector();
searcher.search(new MatchAllDocsQuery(), fc);
Facets facets = new DoubleRangeFacetCounts("field", getDistanceValueSource(), fc,
getBoundingBoxFilter(ORIGIN_LATITUDE, ORIGIN_LONGITUDE, 10.0),
ONE_KM,
TWO_KM,
FIVE_KM,
TEN_KM);
return facets.getTopChildren(10, "field");
}
/** User drills down on the specified range. */
public TopDocs drillDown(DoubleRange range) throws IOException {
// Passing no baseQuery means we drill down on all
// documents ("browse only"):
DrillDownQuery q = new DrillDownQuery(null);
final ValueSource vs = getDistanceValueSource();
q.add("field", range.getFilter(getBoundingBoxFilter(ORIGIN_LATITUDE, ORIGIN_LONGITUDE, range.max), vs));
DrillSideways ds = new DrillSideways(searcher, config, (TaxonomyReader) null) {
@Override
protected Facets buildFacetsResult(FacetsCollector drillDowns, FacetsCollector[] drillSideways, String[] drillSidewaysDims) throws IOException {
assert drillSideways.length == 1;
return new DoubleRangeFacetCounts("field", vs, drillSideways[0], ONE_KM, TWO_KM, FIVE_KM, TEN_KM);
}
};
return ds.search(q, 10).hits;
}
@Override
public void close() throws IOException {
searcher.getIndexReader().close();
indexDir.close();
}
/** Runs the search and drill-down examples and prints the results. */
@SuppressWarnings("unchecked")
public static void main(String[] args) throws Exception {
DistanceFacetsExample example = new DistanceFacetsExample();
example.index();
System.out.println("Distance facet counting example:");
System.out.println("-----------------------");
System.out.println(example.search());
System.out.println("\n");
System.out.println("Distance facet drill-down example (field/< 2 km):");
System.out.println("---------------------------------------------");
TopDocs hits = example.drillDown(example.TWO_KM);
System.out.println(hits.totalHits + " totalHits");
example.close();
}
}