The common answer to this problem is that you have to restart your device. Surely you cannot tell your users to restart device in order for your app to function, so my solution was to use a HTTP fallback, here is the AsyncTask I use in my code. You will have to modify it for … Read more
The key to all of this is understanding map projections. As others have pointed out, the cause of the distortion is the fact that the spherical (or more accurately ellipsoidal) earth is projected onto a plane. In order to achieve your goal, you first must know two things about your data: The projection your maps … Read more
Here’s what worked for me, without so much bs. int x = (int) ((MAP_WIDTH/360.0) * (180 + lon)); int y = (int) ((MAP_HEIGHT/180.0) * (90 – lat)); The lat,lon coordinates were given to me by Android devices. So they should be in the same standard used by all Google Earth/Map products.
I’ve got XML for US state polygons here. I use them like this. I deliberately kept the detail fairly light to reduce the loading time and end up with a map that’s reasonably responsive in slow browsers. I don’t have anything for Canada.
Script its left and top properties as the number of pixels from the left edge and top edge respectively. It must have position: absolute; var d = document.getElementById(‘yourDivId’); d.style.position = “absolute”; d.style.left = x_pos+’px’; d.style.top = y_pos+’px’; Or do it as a function so you can attach it to an event like onmousedown function placeDiv(x_pos, … Read more
The problem you’re trying to solve is the Point in Polygon test. To help visualize the concept of Ray Casting: Draw a Polygon on a piece of paper. Then, starting at any random point, draw a straight line to the right of the page. If your line intersected with your polygon an odd number of … Read more
The atan2 function eases the pain of dealing with atan. It is declared as double atan2(double y, double x) and converts rectangular coordinates (x,y) to the angle theta from the polar coordinates (r,theta) So I’d rewrite your code as public static double angleBetween2Lines(Line2D line1, Line2D line2) { double angle1 = Math.atan2(line1.getY1() – line1.getY2(), line1.getX1() – … Read more
After searching for a long time I finally found this example. Download the example program on the page. It gives you, among other things, the mouse location in the console window (character-based). EDIT: This is my ConsoleListener class (with part of my NativeMethods class). You can attach a handler to the MouseEvent (after calling the … Read more
Here the code modified with the changes suggested by Oren Trutner and from myself: #define degreesToRadians(x) (M_PI * x / 180.0) #define radiansToDegrees(x) (x * 180.0 / M_PI) – (float)getHeadingForDirectionFromCoordinate:(CLLocationCoordinate2D)fromLoc toCoordinate:(CLLocationCoordinate2D)toLoc { float fLat = degreesToRadians(fromLoc.latitude); float fLng = degreesToRadians(fromLoc.longitude); float tLat = degreesToRadians(toLoc.latitude); float tLng = degreesToRadians(toLoc.longitude); float degree = radiansToDegrees(atan2(sin(tLng-fLng)*cos(tLat), cos(fLat)*sin(tLat)-sin(fLat)*cos(tLat)*cos(tLng-fLng))); if (degree … Read more
To ensure that appropriate projection metadata are at every step associated with the coordinates, I’d suggest converting the points to a SpatialPointsDataFrame object as soon as possible. See ?”SpatialPointsDataFrame-class” for more on how to convert simple data.frames or matrices to SpatialPointsDataFrame objects. library(sp) library(rgdal) xy <- data.frame(ID = 1:2, X = c(118, 119), Y = … Read more