org.javarosa.core.util

Class GeoUtils

java.lang.Object

org.javarosa.core.util.GeoUtils

public final class GeoUtils
extends Object

Author: Meletis Margaritis Date: 8/4/14 Time: 1:38 PM

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	GeoUtils.LatLong

Constructor Summary

Constructors

Constructor and Description
GeoUtils()

Method Summary

Modifier and Type	Method and Description
static double	calculateAreaOfGPSPolygonOnEarthInSquareMeters(List<GeoUtils.LatLong> latLongs) Calculates the enclosed area that is defined by a list of gps coordinates on earth.
static double	calculateDistance(List<GeoUtils.LatLong> points) Returns the sum of the distances between points[i] and [i - 1], for all points starting with the second point
static boolean	calculateIsPointInGPSPolygon(GeoUtils.LatLong point, List<GeoUtils.LatLong> polygon) Returns whether a geopoint is inside the specified geoshape; aka 'geofencing'

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GeoUtils

public GeoUtils()

Method Detail

calculateAreaOfGPSPolygonOnEarthInSquareMeters

public static double calculateAreaOfGPSPolygonOnEarthInSquareMeters(List<GeoUtils.LatLong> latLongs)

Calculates the enclosed area that is defined by a list of gps coordinates on earth.

Parameters:

latLongs - the list of coordinates.

Returns:

the enclosed area in square meters (with a double precision).

calculateDistance

public static double calculateDistance(List<GeoUtils.LatLong> points)

Returns the sum of the distances between points[i] and [i - 1], for all points starting with the second point

Parameters:

points - the points between which the distances are to be summed

Returns:

the sum of the distances, in meters

calculateIsPointInGPSPolygon

public static boolean calculateIsPointInGPSPolygon(GeoUtils.LatLong point,
                                                   List<GeoUtils.LatLong> polygon)

Returns whether a geopoint is inside the specified geoshape; aka 'geofencing'

Parameters:

point - the geopoint location to check for inclusion.

polygon - the closed list of geoshape coordinates defining the polygon 'fence'.

Returns:

true if the location is inside the polygon; false otherwise. Adapted from https://wrfranklin.org/Research/Short_Notes/pnpoly.html: int pnpoly(int nvert, float *vertx, float *verty, float testx, float testy) { int i, j, c = 0; for (i = 0, j = nvert - 1; i < nvert; j = i++) { if (((verty[i] > testy) != (verty[j] > testy)) && (testx < (vertx[j] - vertx[i]) * (testy - verty[i]) / (verty[j] - verty[i]) + vertx[i])) c = !c; } return c; }