latitude-longitude

问题 I am creating an Android app which requires finding a coordinate on the same route after X kilometers. I have two coordinates x1,y1 & x2,y2 on a road. Now, my requirement is to find coordinate x3,y3 after some 3 kilometers (i.e., coordinate after x2,y2 not between x1,y1 & x2,y2 ) on the same road. How can this be achieved ? 回答1: If you know the bearing, you can calculate the destination coordinate. Sample Code: private LatLng getDestinationPoint(LatLng source, double brng, double dist) { dist

问题 I retrieve data from the net containing real geodesic expressions, by that I mean degrees, minutes and seconds with Unicode symbols: U+00B0, U+2032 and U+2033 , named Degree, Prime and Double Prime. Example: my $Lat = "48° 25′ 43″ N"; My objective is to convert such an expression first to degrees and then to radians to be used in a Perl module I am writing that implements the Vincenty inverse formula to calculate ellipsoidal great-circle distances. All my code objectives have been met with

问题 I have one data frame with a lot of locations (around 30.000), and I need to convert the time of each location for the local time. I tried some ideas like this one, and this one. But they did not work for me. I have data like this: dt = data.table(date = c("2018-01-16 22:02:37", "2018-01-16 22:54:00", "2018-01-16 23:08:38"), lat = c(-54.5010, -54.5246, -54.5285), long = c(-25.0433, -25.0929, -25.0832)) And I expected this output: date lat long 2018-01-16 20:02:37 -54.5010 -25.0433 2018-01-16

问题 Im working on a script that will pull a variable from my MySQL db table, heres the example coding google gives me. var beaches = [ ['Bondi Beach', -33.890542, 151.274856, 4], ]; and now here is what im trying to achieve, i have a table with the fields, ID , Beach , Long, Lat how would i replace the beach variable to pull from my MySQL table instead of having to go in and manually add the beach to the variable. That way when users add a Beach Name with longitude and latitude to the DB through

问题 I want to pass an array of address to the google maps api, and then in return receive an array of longitude and latitude points. Is this possible? If so could I seen an example on how to construct the url to handle the array? So it would be something like this: http://maps.googleapis.com/maps/api/geocode/xml?latlng=40.714224,-73.961452&sensor=false but i need to pass it address rather than latlng . 回答1: You want a geocoder. Check out the Google docs here: http://code.google.com/apis/maps

问题 I have a unique problem re: projections and obtaining lat/lon coordinates from an image. I have an 800 x 600 pixel image of the U.S., and I know the projection (Polar Sterographic with a -75 lon center of origin), lower left lat/lon, and upper right lat/lon of the image. I've put the image into a webpage and I am able to mouse over the image and obtain the x and y "pixel" coordinates from the image in the div tag. Is there a simple formula to help obtain the lat and lon of the x/y pixel

问题 I have a unique problem re: projections and obtaining lat/lon coordinates from an image. I have an 800 x 600 pixel image of the U.S., and I know the projection (Polar Sterographic with a -75 lon center of origin), lower left lat/lon, and upper right lat/lon of the image. I've put the image into a webpage and I am able to mouse over the image and obtain the x and y "pixel" coordinates from the image in the div tag. Is there a simple formula to help obtain the lat and lon of the x/y pixel

问题 I am working on a project in which I want to make a circle around the location of an item on a google map. In my below code if I click show tab then it should show circle around item's location on a google map: <div class="tab-pane" id="show"> <p> <span class="heading_size">show:</span> </p> <p class="text-justify mb-0 pb-5"> <!-- <? php echo strtolower($data['item']->item_address); ?> --> <div id="map" style="width:100%;height:500px"></div> <script> function myMap() { var amsterdam = new

问题 Is it possible to determine the pixel co-ordinates of a given marker, taking into account current zoom level and visible area of the map? 回答1: Current (v3): map.getProjection().fromLatLngToPoint(marker.position); https://developers.google.com/maps/documentation/javascript/3.exp/reference#Projection Old (v2): The method fromLatLngToContainerPixel following should give you what you're after, assuming markerPoint is your marker, and zoomLevel your current zoom: map.fromLatLngToContainerPixel

问题 I am developing an app using App Inventor. It includes the need for a user to press a button - to save a location when they are at the location. But every time this is not practical. So I want to implement a method in my App Inventor app which will: -Open Google Maps -Let the user select any point on the map with no additional info. -After choosing, return to the app and return latitude, longitude values for the location that is selected. This is really important for me, help will be