It seems you are measuring distance (R) in meters, and bearing (theta) counterclockwise from due east. And for your purposes (hundereds of meters), plane geometry should be accurate enough. In that case, dx = R*cos(theta) ; theta measured counterclockwise from due east dy = R*sin(theta) ; dx, dy same units as R If theta is … Read more
I checked on internet for various polygon area formulas(or code) but did not find any one good or easy to implement. Now I have written the code snippet to calculate area of a polygon drawn on earth surface. The polygon can have n vertices with each vertex has having its own latitude longitude. Few Important … Read more
In your LocationActivity class: Intent i = new Intent(this, FindAndroidActivity.class); i.putExtra(“KEY”,YourData); In FindAndroidActivity class Bundle extras = getIntent().getExtras(); if(extras !=null) { String value = extras.getString(“KEY”); }
A conversion to Swift, taken from this answer: func locationWithBearing(bearingRadians:Double, distanceMeters:Double, origin:CLLocationCoordinate2D) -> CLLocationCoordinate2D { let distRadians = distanceMeters / (6372797.6) // earth radius in meters let lat1 = origin.latitude * M_PI / 180 let lon1 = origin.longitude * M_PI / 180 let lat2 = asin(sin(lat1) * cos(distRadians) + cos(lat1) * sin(distRadians) * cos(bearingRadians)) let … Read more
You can use the Google Geocoder service in the Google Maps API to convert from your location name to a latitude and longitude. So you need some code like: var geocoder = new google.maps.Geocoder(); var address = document.getElementById(“address”).value; geocoder.geocode( { ‘address’: address}, function(results, status) { if (status == google.maps.GeocoderStatus.OK) { // do something with the … Read more
The links provided by @Marcelo & @Doc are good for understanding the derivation of the Lat Lng: http://www.cienciaviva.pt/latlong/anterior/gps.asp?accao=changelang&lang=en https://groups.google.com/forum/?hl=en&fromgroups=#!msg/google-maps-api/oJkyualxzyY/pNv1SE7qpBoJ https://en.wikipedia.org/wiki/Mercator_projection#Mathematics_of_the_Mercator_projection But if you just want an answer for the maximum bounds for Google Maps: Latitude: -85 to +85 (actually -85.05115 for some reason) Longitude: -180 to +180 Try it for yourself on the Google Maps: … Read more
Either of these work google.maps.event.addListener(marker, ‘click’, function (event) { document.getElementById(“latbox”).value = event.latLng.lat(); document.getElementById(“lngbox”).value = event.latLng.lng(); }); google.maps.event.addListener(marker, ‘click’, function (event) { document.getElementById(“latbox”).value = this.getPosition().lat(); document.getElementById(“lngbox”).value = this.getPosition().lng(); }); You might also consider using the dragend event also google.maps.event.addListener(marker, ‘dragend’, function (event) { document.getElementById(“latbox”).value = this.getPosition().lat(); document.getElementById(“lngbox”).value = this.getPosition().lng(); });
Google has a geocoding API which seems to work pretty well for most of the locations that they have Google Maps data for. http://googlemapsapi.blogspot.com/2006/06/geocoding-at-last.html They provide online geocoding (via JavaScript): http://code.google.com/apis/maps/documentation/services.html#Geocoding Or backend geocoding (via an HTTP request): http://code.google.com/apis/maps/documentation/services.html#Geocoding_Direct The data is usually the same used by Google Maps itself. (note that there are some … Read more
Well first of all if you have a lot of geospatial data, you should be using mysql’s geospatial extensions rather than calculations like this. You can then create spatial indexes that would speed up many queries and you don’t have to write long drawn out queries like the one above. Using a comparision with ST_Distance … Read more
If your code runs in a browser, you can use the HTML5 geolocation API: window.navigator.geolocation.getCurrentPosition(function(pos) { console.log(pos); var lat = pos.coords.latitude; var lon = pos.coords.longitude; }) Once you know the current position and the position of your “target”, you can calculate the distance between them in the way documented in this question: Calculate distance between … Read more