latitude-longitude | 易学教程

How to visualise an arrow pointing to a certain coordinates(latitude, longitude), given pich and yaw

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问题 I would like to know how to visualise an arrow pointing to a certain coordinates(latitude, longitude) while I'm moving around holding my handset. I'va calculated the pitch and yaw of the desired position. Now I want to know how to keep pointing to this position while moving. Regards, 回答1: In general you can calculate the bearing angle (the angle between your local meridian and the great circle connecting your current position and the target position measured from the north direction) using

Point on Circle (Longitude/Latitude) in .NET/SQL

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问题 I've got the following problem: I have a table with long/lat values and another table with a project-id and long/lat/radius (circle). Now I need to find out which project matches the long/lat values from the first table. Is there an easy way to do that? 回答1: There are multiple algorithms to calculate distance on sphere, but we use following: create function GetDistance( @latitudeFrom decimal(30,10), @longitudeFrom decimal(30,10), @latitudeTo decimal(30,10), @longitudeTo decimal(30,10) )

Return Nearest Place available to Users location using Latitude-Longitude?

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问题 I want to implement Nearest Place available to User algorithm in Java or MySQL. I have Stations table in MySQL database which has around 100K records of Stations with Latitude and Longitude . If User gives his latitude and longitude as x and y, then I want to return nearest stations available from User's location. So please suggest me any algorithm available in Java or MySQL . I tried with the following query, but it seems slower in performance - SELECT *,3956*2*ASIN(SQRT(POWER(SIN((user_lat

Google maps save marker location?

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So I managed to implement the google map with a dragable marker on my website. The only problem I have now is that I don't know how to save the location of where the marker is put the last time. So if a user drags the marker 4 times, I want to save the location (latitude and longitude) of the 4th time only. This is what I have so far (This is the working code without the code to save the location): <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script> <script type="text/javascript"> var map = new GMap2(document.getElementById("googleMap")); map

stored procedure to get all points inside a bounding box taking into account a negative longitude

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问题 I'm working on a project where I have places with latitude and longitude coordinates stored in my database. I use Google Maps to plot these places as markers on a map. I don't want to plot any "invisible" markers (markers outside the current viewport/bounding box) to the map. Therefore I follow Googles advice regarding viewport marker management. I have a working solution where i use AJAX to query an ASP.NET web service whenever the viewport of my map has changed. This web service calls a

R, get longitude/latitude data for cities and add it to my dataframe [closed]

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问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . I would like to get longitude/latitude data for the cities in my dataframe and add as 2 columns in my frame. I'm new to R and I do not know how to do it. Could someone help me on this My frame: > data <- read.xlsx("example_city.xlsx", 1) > data City Country 1 Stockholm Sweden 2 Oslo Norway 3 Rome Italy 4 Rome

How to compare 2 location positions

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I have an App with a TextView that finds your location and when you move, the value in TextView changes. I want to know what can I do in order to register the first location and then look for the location 5 min after. For example: min 0 LAT 000000 LONG 000000 ( SAVE IT ) min 5 LAT 1111111 LONG 111111 if min0 == min 5 ... To sum up, I want to compare 2 strings (lat & long at the beginning) and lat & long after 5 minutes. Any suggestion will be appreciated. This Link should serve your purpose; Go through distanceTo or distanceBetween . You can create a Location object from a latitude and

MySQL storing Floats

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问题 I am trying to save a float number which is this long 13.00386644742523 Its basically Lat and Lng value. when i save it in the database its getting stored as 13.0039 回答1: Based on experience I did this for a navigation database built from ARINC424 and eventually used a DECIMAL(18,12) for storing values in radians. NOTE : Floats and doubles aren't as precise and may result in rounding errors The point is that when using degrees or radians we know the range of the values - and the fractional

How to test if a point inside area with lat/lon and radius using Java?

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问题 I've to write a method that has the following signature public class Position { double longitude; double latitude; } boolean isInsideTheArea(Position center, double radius, Position point); So if point is inside the area that has the center as its center and radius as its radius in miles , this should return true , false otherwise. 回答1: Use the Haversine formula to compute the distance between center and point . If that distance is greater than radius , return false ; otherwise return true .

How best to perform corridor range search over a set of latitude / longitude coordinates

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问题 What would be the best approach to finding the set of coordinates, from say about 5,00, which lie within a path of points, given a specified width. eg an aircraft following several waypoints. Is there a good way to also sort them in the same order as the route. Calculation speed would be more important than accuracy, since I'm looking at producing a list of suggestions. From what I've looked at, I presume it's not straightforward, and the question is a bit broad, but any suggestions/pointers