geolocation

问题 I'm using various functions from the earthdistance module in PostgreSQL, one of those being ll_to_earth . Given a latitude/longitude combination, I'm trying to retrieve the nearest point from my database via CakePHP 1.2.5 Stable. // set dummy data $latitude = 30.4393696; $longitude = -97.6200043; // create a simple bounding box in the WHERE conditions, sort the points by location, and retrieve the nearest point $location = $this->Location->find('first', array( 'fields' => array( 'id', 'coords

问题 This question already has answers here : Convert latitude and longitude coordinates to country name in R (2 answers) Closed 6 years ago . I have a data frame with lat/lon coordinates: head(COORD) LAT LON 1 69.34 16.17 2 69.20 17.92 3 69.59 17.87 4 69.17 18.52 5 69.42 18.95 6 69.22 18.91 I would like to to retrieve the country name of each point and add it as a third column. Maybe using which in combination with map to retrieve in which polygon the points are but I was not able to figure out

问题 I just noticed that the numbers given by Ads API and the Ads Manager are wildly different. For instance, when searching for the French speakers in the city of Anderlecht, Belgium, the Ads Manager shows 44,000 people and the Ads API gives me the number 12,000 . See the screenshot of the Ads Manager UI and of the curl script calling below: curl -G -q \ -d 'targeting_spec={"geo_locations":{"cities": [{"key":"171194"}]},"locales":[1003]}' \ -d 'access_token=XYZ' \ https://graph.facebook.com/v2.3

问题 Can someone help me using a stored procedure or function to passing my stored varchar lat;lng in table to individuals fields as float as Lat and Lng to use in radius search. lanlng in Table 33.0000;15.222222 Thanks 回答1: Are you just trying to split the string? If so: declare @LatLng varchar(100) set @LatLng = '33.0000;15.222222' declare @Lat float declare @Lng float select @Lat = CAST(LEFT(@LatLng, charindex(';',@LatLng)-1) as float) select @Lng = CAST(SUBSTRING(@LatLng, charindex(';',@LatLng

问题 I'm creating a web request to pull lng and lat data based on zip (using the following url) http://maps.google.com/maps/geo?q=50266 Doing so I get back the following json { "name": "50266", "Status": { "code": 200, "request": "geocode" }, "Placemark": [ { "id": "p1", "address": "West Des Moines, IA 50266, USA", "AddressDetails": { "Accuracy" : 5, "Country" : { "AdministrativeArea" : { "AdministrativeAreaName" : "IA", "Locality" : { "LocalityName" : "West Des Moines", "PostalCode" : {

问题 i'm developing an application for a Restaurant in Portugal called Olivier. Currently I'm studying geolocation api of phonegap, and I haven't find a way to solve my problem that is to check if the user position is inside the restaurant. To be more specific I want my application to show a menu if the user is inside the restaurant area (trough geolocation) and to show a different menu if he's outside the restaurant area. I would be glad if you answer a link to a guide or just write the method i

问题 I'm building a website that uses geolocation in HTML5 to provide a service specific to the region in which the user is. Here is what I have been doing: I use the Javascript in this SO question to get country and administrative region names. Then I search the country and region names in a database and it returns location-specific data that I can display. Here is the script: <script src="https://maps.googleapis.com/maps/api/js?sensor=false"></script> <script> var region = ""; var country = "";

问题 I want to know if I get a lat-long of a user and want to check if he lies in any of the polygon that is stored in my db (MongoDB). How can this be achieved using mongoDB. For instance my db will have 10 polygons stored as GeoJson objects. I get a lat-long and want to check if this lat-long lies in any of the 10 polygons in my DB. Can this be achieved in MongoDB? 回答1: I dont think your particular case can be achieved in MongoDB. MongoDB does have polygon calculations with the $polygon operator

问题 I have a mobile web app where I want to track the latest location for a user, but only if they are in a certain area. But, having a little trouble with excessive prompts on the iPhone There's some location initialization code along the lines of: if (firstTime) { navigator.getCurrentPosition(function (coords) { if (coordsAreInTheBox) { storeCoordsForUser(); navigator.watchPosition(); } }); } else if (userInTheBox) { navigator.watchPosition(); } This works as expected on the first load, there

问题 MKMapViewDelegate's mapView:rendererForOverlay fires when an MKOverlay 's boundingMapRect enters the visible bounds of the MKMapView . Is there an equivalent delegate method that is fired when the MKOverlay leaves the map view's visible bounds? Or do I have to do this math myself? 来源： https://stackoverflow.com/questions/23147789/how-can-i-tell-when-an-mkoverlay-is-no-longer-within-view