有没有办法在 iOS 中获取一组 CLLocationsCoordinate2D 的中心坐标?
问问题
9456 次
6 回答
14
嗯...这取决于您如何定义点的中心。是否取决于分布等...
一个简单的方法如下......
//find rect that encloses all coords
float maxLat = -200;
float maxLong = -200;
float minLat = MAXFLOAT;
float minLong = MAXFLOAT;
for (int i=0 ; i<[locations count] ; i++) {
CLLocationCoordinate2D location = [locations objectAtIndex:i];
if (location.latitude < minLat) {
minLat = location.latitude;
}
if (location.longitude < minLong) {
minLong = location.longitude;
}
if (location.latitude > maxLat) {
maxLat = location.latitude;
}
if (location.longitude > maxLong) {
maxLong = location.longitude;
}
}
//Center point
CLLocationCoordinate2D center = CLLocationCoordinate2DMake((maxLat + minLat) * 0.5, (maxLong + minLong) * 0.5);
这将使矩形的中心覆盖所有点。但是,它没有考虑点差。
IE
. = point
X = centre
..... X .
编辑
修正了一些数学。
于 2013-01-17T08:47:12.047 回答
6
我知道已经很晚了,但是有人可以阅读此内容并帮助自己使用 Fogmeister 答案,您可以创建一个 MKCoordinateRegion
CLLocationDegrees minLat,minLng,maxLat,maxLng;
for(CLLocationCoordinate2D coordinate in coordinates) {
minLat = MIN(minLat, coordinate.latitude);
minLng = MIN(minLng, coordinate.longitude);
maxLat = MAX(maxLat, coordinate.latitude);
maxLng = MAX(maxLng, coordinate.longitude);
}
CLLocationCoordinate2D coordinateOrigin = CLLocationCoordinate2DMake(minLat, minLng);
CLLocationCoordinate2D coordinateMax = CLLocationCoordinate2DMake(maxLat, maxLng);
MKMapPoint upperLeft = MKMapPointForCoordinate(coordinateOrigin);
MKMapPoint lowerRight = MKMapPointForCoordinate(coordinateMax);
//Create the map rect
MKMapRect mapRect = MKMapRectMake(upperLeft.x,
upperLeft.y,
lowerRight.x - upperLeft.x,
lowerRight.y - upperLeft.y);
//Create the region
MKCoordinateRegion region = MKCoordinateRegionForMapRect(mapRect);
//THIS HAS THE CENTER, it should include spread
CLLocationCoordinate2D centerCoordinate = region.center;
问候!!!
于 2013-08-06T03:44:21.023 回答
5
您还可以同时获取s 和 acenter
的数组。CLLocationCoordinate2D
span
extension MKCoordinateRegion {
init(coordinates: [CLLocationCoordinate2D]) {
var minLatitude: CLLocationDegrees = 90.0
var maxLatitude: CLLocationDegrees = -90.0
var minLongitude: CLLocationDegrees = 180.0
var maxLongitude: CLLocationDegrees = -180.0
for coordinate in coordinates {
let lat = Double(coordinate.latitude)
let long = Double(coordinate.longitude)
if lat < minLatitude {
minLatitude = lat
}
if long < minLongitude {
minLongitude = long
}
if lat > maxLatitude {
maxLatitude = lat
}
if long > maxLongitude {
maxLongitude = long
}
}
let span = MKCoordinateSpanMake(maxLatitude - minLatitude, maxLongitude - minLongitude)
let center = CLLocationCoordinate2DMake((maxLatitude - span.latitudeDelta / 2), (maxLongitude - span.longitudeDelta / 2))
self.init(center: center, span: span)
}
}
用法:
let region = MKCoordinateRegion(coordinates: coordinates)
region.center
region.span
于 2017-12-07T12:30:29.500 回答
4
和 Swift 5 兼容的扩展
extension Array where Element == CLLocationCoordinate2D {
func center() -> CLLocationCoordinate2D {
var maxLatitude: Double = -200;
var maxLongitude: Double = -200;
var minLatitude: Double = Double(MAXFLOAT);
var minLongitude: Double = Double(MAXFLOAT);
for location in self {
if location.latitude < minLatitude {
minLatitude = location.latitude;
}
if location.longitude < minLongitude {
minLongitude = location.longitude;
}
if location.latitude > maxLatitude {
maxLatitude = location.latitude;
}
if location.longitude > maxLongitude {
maxLongitude = location.longitude;
}
}
return CLLocationCoordinate2DMake(CLLocationDegrees((maxLatitude + minLatitude) * 0.5), CLLocationDegrees((maxLongitude + minLongitude) * 0.5));
}
}
于 2020-01-07T20:41:41.250 回答
1
如果您正在寻找作为中心的平均值,那么您将所有纬度和经度相加成它们自己的总数,然后除以您拥有的坐标数,这是非常标准的数学。
(请注意,如果您的坐标跨越日期线,这将不起作用)
于 2013-01-17T19:39:52.623 回答
1
Fogmeisters 的回答会起作用,但有 3 个错误,我已在下面更正:
//find rect that encloses all coords
float maxLat = -200;
float maxLong = -200;
float minLat = MAXFLOAT;
float minLong = MAXFLOAT;
for (int i=0 ; i<[locations count] ; i++) {
CLLocationCoordinate2D location = [locations objectAtIndex:i];
if (location.latitude < minLat) {
minLat = location.latitude;
}
if (location.longitude < minLong) {
minLong = location.longitude;
}
if (location.latitude > maxLat) {
maxLat = location.latitude;
}
if (location.longitude > maxLong) { //Change to be greater than
maxLong = location.longitude;
}
}
//Center point
//The min's and max's should be ADDED not subtracted
CLLocationCoordinate2D center = CLLocationCoordinate2DMake((maxLat + minLat) * 0.5, (maxLong + minLong) * 0.5);
于 2014-01-15T12:48:35.500 回答