map

问题 I am writting web application using only angularjs. I am currently using Leaflet to display a map on a webpage. I am able to display a map succesfully with out any problems, I am also using leaflet.draw to draw a rectangle and to get all 4 coordinates. Now, what I want to do is to do this same thing but offline. I want to user to be able to use this application without internet conectivity. I want to user to see America and Atlantic Ocean and be able to zoom in several levels. I dont need

问题 How do I calculate the angle in degrees between the coordinates of two POIs (points of interest) on an iPhone map application? 回答1: I'm guessing you try to calculate the degrees between the coordinates of two points of interest (POI). Calculating the arc of a great circle: +(float) greatCircleFrom:(CLLocation*)first to:(CLLocation*)second { int radius = 6371; // 6371km is the radius of the earth float dLat = second.coordinate.latitude-first.coordinate.latitude; float dLon = second.coordinate

问题 This question already has answers here : What is difference between const and non const key? (7 answers) Closed 6 years ago . When defining a std::map , does it make sense to make the key type const ? 回答1: The key is already const , actually, because a key cannot change once an element was inserted in the map. 来源： https://stackoverflow.com/questions/6307321/does-it-make-sense-to-make-stdmap-key-const

问题 I have a downloader function that downloads multiple files parallely. I use multiprocessing.Pool.map_async in order to download different chunks of the same file. I would like to show a statusbar of the download. For this, I need to know the total bytes that has been already downloaded ( total_bytes_dl ). pool = multiprocessing.Pool(processes) mapObj = pool.map_async(f, args) while not mapObj.ready(): status = r"%.2f MB / %.2f MB" % (total_bytes_dl / 1024.0 / 1024.0, filesize / 1024.0 / 1024

问题 I have a downloader function that downloads multiple files parallely. I use multiprocessing.Pool.map_async in order to download different chunks of the same file. I would like to show a statusbar of the download. For this, I need to know the total bytes that has been already downloaded ( total_bytes_dl ). pool = multiprocessing.Pool(processes) mapObj = pool.map_async(f, args) while not mapObj.ready(): status = r"%.2f MB / %.2f MB" % (total_bytes_dl / 1024.0 / 1024.0, filesize / 1024.0 / 1024

问题 is it possible to create different coloured polygons on a map view using the following method? -(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id )overlay{ say if i had 2 polygons could i set one to red and the other to yellow? 回答1: One way is to use the title property to tell one polygon from another. When adding the polygons, set their title accordingly: pone.title = @"one"; [mapView addOverlay:pone]; pother.title = @"other"; [mapView addOverlay:pother]; Then in

问题 If I have two stl vectors vect1, vect2 and I want to produce from them a map, so first element from vect1 will correspond to first element in vect2 and so on. How can I do that in the most simple way? 回答1: std::vector<int> a, b; // fill vectors here... std::map<int, int> m; assert(a.size() == b.size()); for (size_t i = 0; i < a.size(); ++i) m[a[i]] = b[i]; 回答2: Here is a solution that uses standard library functions (and C++0x lambdas). const int data1[] = { 0, 2, 4, 6, 8 }; const int data2[]

问题 If I have two stl vectors vect1, vect2 and I want to produce from them a map, so first element from vect1 will correspond to first element in vect2 and so on. How can I do that in the most simple way? 回答1: std::vector<int> a, b; // fill vectors here... std::map<int, int> m; assert(a.size() == b.size()); for (size_t i = 0; i < a.size(); ++i) m[a[i]] = b[i]; 回答2: Here is a solution that uses standard library functions (and C++0x lambdas). const int data1[] = { 0, 2, 4, 6, 8 }; const int data2[]

问题 I really need some help with the OSMdroid library. It is useful to have maps stored in sdcard as zip files. Also, maps can be unzipped and the image files may be used directly for faster rendering. I managed to load tiles from my sdcard when the tiles are unziiped , have .tile extension and are stored in the folder /sdcard/osmdroid/tiles/Mapnik/... To create my map I used the Mobile Atlas Creator and OSMAND tile storage format. I read some tutorials on the web that claim storing zip files

问题 I really need some help with the OSMdroid library. It is useful to have maps stored in sdcard as zip files. Also, maps can be unzipped and the image files may be used directly for faster rendering. I managed to load tiles from my sdcard when the tiles are unziiped , have .tile extension and are stored in the folder /sdcard/osmdroid/tiles/Mapnik/... To create my map I used the Mobile Atlas Creator and OSMAND tile storage format. I read some tutorials on the web that claim storing zip files