org.elasticsearch.common.geo.GeoUtils Maven / Gradle / Ivy
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/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.common.geo;
import org.apache.lucene.util.SloppyMath;
import org.elasticsearch.ElasticsearchParseException;
import org.elasticsearch.common.unit.DistanceUnit;
import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
import org.elasticsearch.common.xcontent.support.XContentMapValues;
import org.elasticsearch.index.fielddata.FieldData;
import org.elasticsearch.index.fielddata.GeoPointValues;
import org.elasticsearch.index.fielddata.MultiGeoPointValues;
import org.elasticsearch.index.fielddata.NumericDoubleValues;
import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
import org.elasticsearch.index.fielddata.SortingNumericDoubleValues;
import org.elasticsearch.xcontent.NamedXContentRegistry;
import org.elasticsearch.xcontent.XContentParser;
import org.elasticsearch.xcontent.support.MapXContentParser;
import java.io.IOException;
import java.util.Collections;
public class GeoUtils {
/** Maximum valid latitude in degrees. */
public static final double MAX_LAT = 90.0;
/** Minimum valid latitude in degrees. */
public static final double MIN_LAT = -90.0;
/** Maximum valid longitude in degrees. */
public static final double MAX_LON = 180.0;
/** Minimum valid longitude in degrees. */
public static final double MIN_LON = -180.0;
public static final String LATITUDE = "lat";
public static final String LONGITUDE = "lon";
public static final String GEOHASH = "geohash";
public static final String COORDINATES = "coordinates";
public static final String TYPE = "type";
/** Earth ellipsoid major axis defined by WGS 84 in meters */
public static final double EARTH_SEMI_MAJOR_AXIS = 6378137.0; // meters (WGS 84)
/** Earth ellipsoid minor axis defined by WGS 84 in meters */
public static final double EARTH_SEMI_MINOR_AXIS = 6356752.314245; // meters (WGS 84)
/** Earth mean radius defined by WGS 84 in meters */
public static final double EARTH_MEAN_RADIUS = 6371008.7714D; // meters (WGS 84)
/** Earth axis ratio defined by WGS 84 (0.996647189335) */
public static final double EARTH_AXIS_RATIO = EARTH_SEMI_MINOR_AXIS / EARTH_SEMI_MAJOR_AXIS;
/** Earth ellipsoid equator length in meters */
public static final double EARTH_EQUATOR = 2 * Math.PI * EARTH_SEMI_MAJOR_AXIS;
/** Earth ellipsoid polar distance in meters */
public static final double EARTH_POLAR_DISTANCE = Math.PI * EARTH_SEMI_MINOR_AXIS;
/** rounding error for quantized latitude and longitude values */
public static final double TOLERANCE = 1E-6;
private static final int QUAD_MAX_LEVELS_POSSIBLE = 50;
private static final int GEOHASH_MAX_LEVELS_POSSIBLE = 24;
/** Returns true if latitude is actually a valid latitude value.*/
public static boolean isValidLatitude(double latitude) {
if (Double.isNaN(latitude) || Double.isInfinite(latitude) || latitude < GeoUtils.MIN_LAT || latitude > GeoUtils.MAX_LAT) {
return false;
}
return true;
}
/** Returns true if longitude is actually a valid longitude value. */
public static boolean isValidLongitude(double longitude) {
if (Double.isNaN(longitude) || Double.isInfinite(longitude) || longitude < GeoUtils.MIN_LON || longitude > GeoUtils.MAX_LON) {
return false;
}
return true;
}
/**
* Calculate the width (in meters) of geohash cells at a specific level
* @param level geohash level must be greater or equal to zero
* @return the width of cells at level in meters
*/
public static double geoHashCellWidth(int level) {
assert level >= 0;
// Geohash cells are split into 32 cells at each level. the grid
// alternates at each level between a 8x4 and a 4x8 grid
return EARTH_EQUATOR / (1L << ((((level + 1) / 2) * 3) + ((level / 2) * 2)));
}
/**
* Calculate the width (in meters) of quadtree cells at a specific level
* @param level quadtree level must be greater or equal to zero
* @return the width of cells at level in meters
*/
public static double quadTreeCellWidth(int level) {
assert level >= 0;
return EARTH_EQUATOR / (1L << level);
}
/**
* Calculate the height (in meters) of geohash cells at a specific level
* @param level geohash level must be greater or equal to zero
* @return the height of cells at level in meters
*/
public static double geoHashCellHeight(int level) {
assert level >= 0;
// Geohash cells are split into 32 cells at each level. the grid
// alternates at each level between a 8x4 and a 4x8 grid
return EARTH_POLAR_DISTANCE / (1L << ((((level + 1) / 2) * 2) + ((level / 2) * 3)));
}
/**
* Calculate the height (in meters) of quadtree cells at a specific level
* @param level quadtree level must be greater or equal to zero
* @return the height of cells at level in meters
*/
public static double quadTreeCellHeight(int level) {
assert level >= 0;
return EARTH_POLAR_DISTANCE / (1L << level);
}
/**
* Calculate the size (in meters) of geohash cells at a specific level
* @param level geohash level must be greater or equal to zero
* @return the size of cells at level in meters
*/
public static double geoHashCellSize(int level) {
assert level >= 0;
final double w = geoHashCellWidth(level);
final double h = geoHashCellHeight(level);
return Math.sqrt(w * w + h * h);
}
/**
* Calculate the size (in meters) of quadtree cells at a specific level
* @param level quadtree level must be greater or equal to zero
* @return the size of cells at level in meters
*/
public static double quadTreeCellSize(int level) {
assert level >= 0;
return Math.sqrt(EARTH_POLAR_DISTANCE * EARTH_POLAR_DISTANCE + EARTH_EQUATOR * EARTH_EQUATOR) / (1L << level);
}
/**
* Calculate the number of levels needed for a specific precision. Quadtree
* cells will not exceed the specified size (diagonal) of the precision.
* @param meters Maximum size of cells in meters (must greater than zero)
* @return levels need to achieve precision
*/
public static int quadTreeLevelsForPrecision(double meters) {
assert meters >= 0;
if (meters == 0) {
return QUAD_MAX_LEVELS_POSSIBLE;
} else {
final double ratio = 1 + (EARTH_POLAR_DISTANCE / EARTH_EQUATOR); // cell ratio
final double width = Math.sqrt((meters * meters) / (ratio * ratio)); // convert to cell width
final long part = Math.round(Math.ceil(EARTH_EQUATOR / width));
final int level = Long.SIZE - Long.numberOfLeadingZeros(part) - 1; // (log_2)
return (part <= (1L << level)) ? level : (level + 1); // adjust level
}
}
/**
* Calculate the number of levels needed for a specific precision. QuadTree
* cells will not exceed the specified size (diagonal) of the precision.
* @param distance Maximum size of cells as unit string (must greater or equal to zero)
* @return levels need to achieve precision
*/
public static int quadTreeLevelsForPrecision(String distance) {
return quadTreeLevelsForPrecision(DistanceUnit.METERS.parse(distance, DistanceUnit.DEFAULT));
}
/**
* Calculate the number of levels needed for a specific precision. GeoHash
* cells will not exceed the specified size (diagonal) of the precision.
* @param meters Maximum size of cells in meters (must greater or equal to zero)
* @return levels need to achieve precision
*/
public static int geoHashLevelsForPrecision(double meters) {
assert meters >= 0;
if (meters == 0) {
return GEOHASH_MAX_LEVELS_POSSIBLE;
} else {
final double ratio = 1 + (EARTH_POLAR_DISTANCE / EARTH_EQUATOR); // cell ratio
final double width = Math.sqrt((meters * meters) / (ratio * ratio)); // convert to cell width
final double part = Math.ceil(EARTH_EQUATOR / width);
if (part == 1) return 1;
final int bits = (int) Math.round(Math.ceil(Math.log(part) / Math.log(2)));
final int full = bits / 5; // number of 5 bit subdivisions
final int left = bits - full * 5; // bit representing the last level
final int even = full + (left > 0 ? 1 : 0); // number of even levels
final int odd = full + (left > 3 ? 1 : 0); // number of odd levels
return even + odd;
}
}
/**
* Calculate the number of levels needed for a specific precision. GeoHash
* cells will not exceed the specified size (diagonal) of the precision.
* @param distance Maximum size of cells as unit string (must greater or equal to zero)
* @return levels need to achieve precision
*/
public static int geoHashLevelsForPrecision(String distance) {
return geoHashLevelsForPrecision(DistanceUnit.METERS.parse(distance, DistanceUnit.DEFAULT));
}
/**
* Normalize longitude to lie within the -180 (exclusive) to 180 (inclusive) range.
*
* @param lon Longitude to normalize
* @return The normalized longitude.
*/
public static double normalizeLon(double lon) {
if (lon > 180d || lon <= -180d) {
lon = centeredModulus(lon, 360);
}
// avoid -0.0
return lon + 0d;
}
/**
* Normalize latitude to lie within the -90 to 90 (both inclusive) range.
*
* Note: You should not normalize longitude and latitude separately,
* because when normalizing latitude it may be necessary to
* add a shift of 180° in the longitude.
* For this purpose, you should call the
* {@link #normalizePoint(GeoPoint)} function.
*
* @param lat Latitude to normalize
* @return The normalized latitude.
* @see #normalizePoint(GeoPoint)
*/
public static double normalizeLat(double lat) {
if (lat > 90d || lat < -90d) {
lat = centeredModulus(lat, 360);
if (lat < -90) {
lat = -180 - lat;
} else if (lat > 90) {
lat = 180 - lat;
}
}
// avoid -0.0
return lat + 0d;
}
/**
* Normalize the geo {@code Point} for its coordinates to lie within their
* respective normalized ranges.
*
* Note: A shift of 180° is applied in the longitude if necessary,
* in order to normalize properly the latitude.
*
* @param point The point to normalize in-place.
*/
public static void normalizePoint(GeoPoint point) {
normalizePoint(point, true, true);
}
/**
* Normalize the geo {@code Point} for the given coordinates to lie within
* their respective normalized ranges.
*
* You can control which coordinate gets normalized with the two flags.
*
* Note: A shift of 180° is applied in the longitude if necessary,
* in order to normalize properly the latitude.
* If normalizing latitude but not longitude, it is assumed that
* the longitude is in the form x+k*360, with x in ]-180;180],
* and k is meaningful to the application.
* Therefore x will be adjusted while keeping k preserved.
*
* @param point The point to normalize in-place.
* @param normLat Whether to normalize latitude or leave it as is.
* @param normLon Whether to normalize longitude.
*/
public static void normalizePoint(GeoPoint point, boolean normLat, boolean normLon) {
double[] pt = { point.lon(), point.lat() };
normalizePoint(pt, normLon, normLat);
point.reset(pt[1], pt[0]);
}
public static void normalizePoint(double[] lonLat) {
normalizePoint(lonLat, true, true);
}
public static boolean needsNormalizeLat(double lat) {
return lat > 90 || lat < -90;
}
public static boolean needsNormalizeLon(double lon) {
return lon > 180 || lon < -180;
}
public static void normalizePoint(double[] lonLat, boolean normLon, boolean normLat) {
assert lonLat != null && lonLat.length == 2;
normLat = normLat && needsNormalizeLat(lonLat[1]);
normLon = normLon && (needsNormalizeLon(lonLat[0]) || normLat);
if (normLat) {
lonLat[1] = centeredModulus(lonLat[1], 360);
boolean shift = true;
if (lonLat[1] < -90) {
lonLat[1] = -180 - lonLat[1];
} else if (lonLat[1] > 90) {
lonLat[1] = 180 - lonLat[1];
} else {
// No need to shift the longitude, and the latitude is normalized
shift = false;
}
if (shift) {
if (normLon) {
lonLat[0] += 180;
} else {
// Longitude won't be normalized,
// keep it in the form x+k*360 (with x in ]-180;180])
// by only changing x, assuming k is meaningful for the user application.
lonLat[0] += normalizeLon(lonLat[0]) > 0 ? -180 : 180;
}
}
}
if (normLon) {
lonLat[0] = centeredModulus(lonLat[0], 360);
}
}
public static double centeredModulus(double dividend, double divisor) {
double rtn = dividend % divisor;
if (rtn <= 0) {
rtn += divisor;
}
if (rtn > divisor / 2) {
rtn -= divisor;
}
return rtn;
}
/**
* Parse a {@link GeoPoint} with a {@link XContentParser}:
*
* @param parser {@link XContentParser} to parse the value from
* @return new {@link GeoPoint} parsed from the parse
*/
public static GeoPoint parseGeoPoint(XContentParser parser) throws IOException, ElasticsearchParseException {
return parseGeoPoint(parser, false);
}
/**
* Parses the value as a geopoint. The following types of values are supported:
*
* Object: has to contain either lat and lon or geohash or type and coordinates fields
*
* String: expected to be in "latitude, longitude" format or a geohash
*
* Array: two or more elements, the first element is longitude, the second is latitude, the rest is ignored if ignoreZValue is true
*/
public static GeoPoint parseGeoPoint(Object value, final boolean ignoreZValue) throws ElasticsearchParseException {
try (
XContentParser parser = new MapXContentParser(
NamedXContentRegistry.EMPTY,
LoggingDeprecationHandler.INSTANCE,
Collections.singletonMap("null_value", value),
null
)
) {
parser.nextToken(); // start object
parser.nextToken(); // field name
parser.nextToken(); // field value
return parseGeoPoint(parser, ignoreZValue);
} catch (IOException ex) {
throw new ElasticsearchParseException("error parsing geopoint", ex);
}
}
/**
* Represents the point of the geohash cell that should be used as the value of geohash
*/
public enum EffectivePoint {
TOP_LEFT,
TOP_RIGHT,
BOTTOM_LEFT,
BOTTOM_RIGHT
}
/**
* Parse a geopoint represented as an object, string or an array. If the geopoint is represented as a geohash,
* the left bottom corner of the geohash cell is used as the geopoint coordinates.GeoBoundingBoxQueryBuilder.java
*/
public static GeoPoint parseGeoPoint(XContentParser parser, final boolean ignoreZValue) throws IOException,
ElasticsearchParseException {
return parseGeoPoint(parser, ignoreZValue, EffectivePoint.BOTTOM_LEFT);
}
/**
* Parse a {@link GeoPoint} with a {@link XContentParser}. A geo_point has one of the following forms:
*
*
* - Object:
{"lat": <latitude>, "lon": <longitude>}
* - Object:
{"type": Point, "coordinates": <array of doubles>}
* - String:
"<latitude>,<longitude>"
* - Geohash:
"<geohash>"
* - Array:
[<longitude>,<latitude>]
*
*
* @param parser {@link XContentParser} to parse the value from
* @param ignoreZValue {@link XContentParser} to not throw an error if 3 dimensional data is provided
* @return new {@link GeoPoint} parsed from the parse
*/
public static GeoPoint parseGeoPoint(XContentParser parser, final boolean ignoreZValue, final EffectivePoint effectivePoint)
throws IOException, ElasticsearchParseException {
return geoPointParser.parsePoint(parser, ignoreZValue, value -> {
GeoPoint point = new GeoPoint();
point.resetFromString(value, ignoreZValue, effectivePoint);
return point;
}, value -> {
GeoPoint point = new GeoPoint();
point.parseGeoHash(value, effectivePoint);
return point;
});
}
private static GenericPointParser geoPointParser = new GenericPointParser<>("geo_point", "lon", "lat", true) {
@Override
public void assertZValue(boolean ignoreZValue, double zValue) {
GeoPoint.assertZValue(ignoreZValue, zValue);
}
@Override
public GeoPoint createPoint(double x, double y) {
// GeoPoint takes lat,lon which is the reverse order from CartesianPoint
return new GeoPoint(y, x);
}
@Override
public String fieldError() {
return "field must be either lat/lon, geohash string or type/coordinates";
}
};
/**
* Parse a {@link GeoPoint} from a string. The string must have one of the following forms:
*
*
* - Latitude, Longitude form:
"<latitude>,<longitude>"
* - Geohash form::
"<geohash>"
*
*
* @param val a String to parse the value from
* @return new parsed {@link GeoPoint}
*/
public static GeoPoint parseFromString(String val) {
GeoPoint point = new GeoPoint();
return point.resetFromString(val, false, EffectivePoint.BOTTOM_LEFT);
}
/**
* Parse a precision that can be expressed as an integer or a distance measure like "1km", "10m".
*
* The precision is expressed as a number between 1 and 12 and indicates the length of geohash
* used to represent geo points.
*
* @param parser {@link XContentParser} to parse the value from
* @return int representing precision
*/
public static int parsePrecision(XContentParser parser) throws IOException, ElasticsearchParseException {
XContentParser.Token token = parser.currentToken();
if (token.equals(XContentParser.Token.VALUE_NUMBER)) {
return XContentMapValues.nodeIntegerValue(parser.intValue());
} else {
String precision = parser.text();
try {
// we want to treat simple integer strings as precision levels, not distances
return XContentMapValues.nodeIntegerValue(precision);
} catch (NumberFormatException e) {
// try to parse as a distance value
final int parsedPrecision = GeoUtils.geoHashLevelsForPrecision(precision);
try {
return checkPrecisionRange(parsedPrecision);
} catch (IllegalArgumentException e2) {
// this happens when distance too small, so precision > 12. We'd like to see the original string
throw new IllegalArgumentException("precision too high [" + precision + "]", e2);
}
}
}
}
/**
* Checks that the precision is within range supported by elasticsearch - between 1 and 12
*
* Returns the precision value if it is in the range and throws an IllegalArgumentException if it
* is outside the range.
*/
public static int checkPrecisionRange(int precision) {
if ((precision < 1) || (precision > 12)) {
throw new IllegalArgumentException("Invalid geohash aggregation precision of " + precision + ". Must be between 1 and 12.");
}
return precision;
}
/** Returns the maximum distance/radius (in meters) from the point 'center' before overlapping */
public static double maxRadialDistanceMeters(final double centerLat, final double centerLon) {
if (Math.abs(centerLat) == MAX_LAT) {
return SloppyMath.haversinMeters(centerLat, centerLon, 0, centerLon);
}
return SloppyMath.haversinMeters(centerLat, centerLon, centerLat, (MAX_LON + centerLon) % 360);
}
/** Return the distance (in meters) between 2 lat,lon geo points using the haversine method implemented by lucene */
public static double arcDistance(double lat1, double lon1, double lat2, double lon2) {
return SloppyMath.haversinMeters(lat1, lon1, lat2, lon2);
}
/**
* Return the distance (in meters) between 2 lat,lon geo points using a simple tangential plane
* this provides a faster alternative to {@link GeoUtils#arcDistance} but is inaccurate for distances greater than
* 4 decimal degrees
*/
public static double planeDistance(double lat1, double lon1, double lat2, double lon2) {
double x = Math.toRadians(lon2 - lon1) * Math.cos(Math.toRadians((lat2 + lat1) / 2.0));
double y = Math.toRadians(lat2 - lat1);
return Math.sqrt(x * x + y * y) * EARTH_MEAN_RADIUS;
}
/**
* Return a {@link SortedNumericDoubleValues} instance that returns the distances to a list of geo-points
* for each document.
*/
public static SortedNumericDoubleValues distanceValues(
final GeoDistance distance,
final DistanceUnit unit,
final MultiGeoPointValues geoPointValues,
final GeoPoint... fromPoints
) {
final GeoPointValues singleValues = FieldData.unwrapSingleton(geoPointValues);
if (singleValues != null && fromPoints.length == 1) {
return FieldData.singleton(new NumericDoubleValues() {
@Override
public boolean advanceExact(int doc) throws IOException {
return singleValues.advanceExact(doc);
}
@Override
public double doubleValue() throws IOException {
final GeoPoint from = fromPoints[0];
final GeoPoint to = singleValues.geoPointValue();
return distance.calculate(from.lat(), from.lon(), to.lat(), to.lon(), unit);
}
});
} else {
return new SortingNumericDoubleValues() {
@Override
public boolean advanceExact(int target) throws IOException {
if (geoPointValues.advanceExact(target)) {
resize(geoPointValues.docValueCount() * fromPoints.length);
int v = 0;
for (int i = 0; i < geoPointValues.docValueCount(); ++i) {
final GeoPoint point = geoPointValues.nextValue();
for (GeoPoint from : fromPoints) {
values[v] = distance.calculate(from.lat(), from.lon(), point.lat(), point.lon(), unit);
v++;
}
}
sort();
return true;
} else {
return false;
}
}
};
}
}
private GeoUtils() {}
}