latitude-longitude

问题 For each coordinate I have, I find the distance from the equator in kilometers giving me two distances: from pyproj import Geod wgs84_geod = Geod(ellps='WGS84') _,_, lon_dist = wgs84_geod.inv(0, 0,lon, 0) _,_, lat_dist = wgs84_geod.inv(0, 0,0, lat) As a sanity check,I can recalculate the original coordinate from these values as follows (assume the direction from the equator coordinate (0,0) is North and West: _, new_lat, _ = wgs84_geod.fwd(0,0, 0, lat_dist) new_lon, _, _ = wgs84_geod.fwd(0, 0

问题 OK, here's what I want to implement and I need your ideas : Input a geo location by name/address/etc (e.g. London, Oxford Street 20 ) Get the point's longitude/latitude My Questions : How would you go about that? Is using Google Maps API (that's what I first thought of) my only solution? It'd be better if the service used CAN be freely integrated in a commercial app - so any idea is welcome... :-) 回答1: There is a built in API for that. For iOS 5 and newer you can use CLGeocoder and for older

问题 I've been breaking my head the greater part of the day on getting correct output from longitude and latitude data. I know this data is correct by plotting it in google maps. For example I will show the data for these lat and long coordinates: Longitude: 4.905396 Latitude: 52.364643 When plotted in google maps it shows the correct location which is Amsterdam in The Netherlands: Now when I plot this in my application it looks as follows: And yes google maps is a 2D representation and mine is 3D

问题 I am calculating center Lat/Lng fron list of available Lat/Lng using C# and rendering on OpenLayer Map. I observed the calculation of getting center lat/lng will give me slightly difference in lat/lng . I am referring this link for the calculation Calculate the center point of multiple latitude/longitude coordinate pairs. C# Code: static void Main(string[] args) { List<GeoCoordinate> listCoordinate = new List<GeoCoordinate>(); listCoordinate.Add(new GeoCoordinate() { Latitude = 22.9833,

问题 I'm trying to divide the map of an area into 1 km x 1 km square grids and ultimately, count and retrieve how many points (given their latitude and longitude values) fall into each square grid of this map. Can this operation be done in the PostGIS, if so, how can I do that? UPDATE: Mike Toews has a detailed answer here: https://gis.stackexchange.com/questions/16374/how-to-create-a-regular-polygon-grid-in-postgis 回答1: As mentioned in my comment make a regular grid. To make a 1 km grid for a

问题 I am trying to scrape user location with respect to user names from twitter. Input: The user list has more than 50K User names AkkiPritam,6.77E+17,12/15/2015,#chennaifloods AkkiPritam,6.77E+17,12/15/2015,#bhoomikatrust AkkiPritam,6.77E+17,12/15/2015,#akshaykumar gischethans,6.77E+17,12/15/2015,#chennaifloods mid_day,6.77E+17,12/15/2015,#bollywood mid_day,6.77E+17,12/15/2015,#chennaifloods Nanthivarman16,6.77E+17,12/15/2015,#admkfails Nanthivarman16,6.77E+17,12/15/2015,#jayafails

问题 I am trying to scrape user location with respect to user names from twitter. Input: The user list has more than 50K User names AkkiPritam,6.77E+17,12/15/2015,#chennaifloods AkkiPritam,6.77E+17,12/15/2015,#bhoomikatrust AkkiPritam,6.77E+17,12/15/2015,#akshaykumar gischethans,6.77E+17,12/15/2015,#chennaifloods mid_day,6.77E+17,12/15/2015,#bollywood mid_day,6.77E+17,12/15/2015,#chennaifloods Nanthivarman16,6.77E+17,12/15/2015,#admkfails Nanthivarman16,6.77E+17,12/15/2015,#jayafails

问题 I am trying to scrape user location with respect to user names from twitter. Input: The user list has more than 50K User names AkkiPritam,6.77E+17,12/15/2015,#chennaifloods AkkiPritam,6.77E+17,12/15/2015,#bhoomikatrust AkkiPritam,6.77E+17,12/15/2015,#akshaykumar gischethans,6.77E+17,12/15/2015,#chennaifloods mid_day,6.77E+17,12/15/2015,#bollywood mid_day,6.77E+17,12/15/2015,#chennaifloods Nanthivarman16,6.77E+17,12/15/2015,#admkfails Nanthivarman16,6.77E+17,12/15/2015,#jayafails

问题 I'm trying to capture tweets using twitter4j's streaming methods from the area of Hongkong. However not matter what latitude or longitude coordinates I choose to do so (from http://www.latlong.net/convert-address-to-lat-long.html) I always get invalid latitude/longitude error. Latitude/longitude are not valid: 22.27, 114.17, 22.35, 114.21 The code I use is otherwise working fine: TwitterStream twitterStream = new TwitterStreamFactory(cb.build()).getInstance(); FilterQuery fq = new FilterQuery

问题 I found a piece of code on web. It calculates the Minimum bounding rectangle by a given lat/lon point and a distance. private static void GetlatLon(double LAT, double LON, double distance, double angle, out double newLon, out double newLat) { double dx = distance * 1000 * Math.Sin(angle * Math.PI / 180.0); double dy = distance * 1000 * Math.Cos(angle * Math.PI / 180.0); double ec = 6356725 + 21412 * (90.0 - LAT) / 90.0; double ed = ec * Math.Cos(LAT * Math.PI / 180); newLon = (dx / ed + LON *