## Moving a CLLocation by x meters

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

## mySQL longitude and latitude query for other rows within x mile radius

Here is the query I use on the store locator I work with: SELECT `id`, ( 6371 * acos( cos( radians( :lat ) ) * cos( radians( `lat` ) ) * cos( radians( `long` ) – radians( :long ) ) + sin(radians(:lat)) * sin(radians(`lat`)) ) ) `distance` FROM `location` HAVING `distance` < :distance ORDER BY … Read more

## Get latitude and longitude based on location name with Google Autocomplete API

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

## Retrieve latitude and longitude of a draggable pin via Google Maps API V3

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(); });

## Whats the fastest way to lookup big tables for points within radius MySQL (latitude longitude)

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

## How to find my distance to a known location in JavaScript

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

## Calculate second point knowing the starting point and distance

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

## Converting longitude/latitude to X/Y coordinate

The big issue with plotting maps is that the spherical surface of the Earth cannot be conveniently converted into a flat representation. There are a bunch of different projections that attempt to resolve this. Mercator is one of the simplest: it assumes that lines of equal latitude are parallel horizontals, while lines of equal longitude … Read more

## Trilateration using 3 latitude and longitude points, and 3 distances

Wikipedia gives a pretty thorough discussion of the algebra here: http://en.wikipedia.org/wiki/Trilateration The first step, not really covered in the Wikipedia entry, is to convert your lat/long coordinates to Cartesian coordinates: x0 = cos( lon0 ) * cos( lat0 ) , y0 = sin( lon0 ) * cos( lat0 ) , z0 = sin( lat0 ) … Read more

## What datatype to use when storing latitude and longitude data in SQL databases? [duplicate]

For latitudes use: Decimal(8,6), and longitudes use: Decimal(9,6) If you’re not used to precision and scale parameters, here’s a format string visual: Latitude and Longitude ##.###### and ###.###### To 6 decimal places should get you to around ~10cm of accuracy on a coordinate.

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