您可以创建一个
struct
用于保存最小/最大经度和纬度值,然后使用
reduce
,其中使用这些的初始值创建初始结果,然后创建
结构
有必要的
min
/
max
计算。
struct MinMaxCoordinates {
let maxLong:Double
let maxLat:Double
let minLong:Double
let minLat:Double
}
let minMaxCoordinates = inCoordinates.reduce(MinMaxCoordinates(maxLong: -180, maxLat: -180, minLong: 180, minLat: 180), {minMax, coord in
return MinMaxCoordinates(maxLong: max(minMax.maxLong, coord.longitude), maxLat: max(minMax.maxLat, coord.latitude), minLong: min(minMax.minLong, coord.longitude), minLat: max(minMax.minLat, coord.latitude))
})
let nw: CLLocation = CLLocation(latitude: minMaxCoordinates.maxLat, longitude: minMaxCoordinates.minLong)
let se: CLLocation = CLLocation(latitude: minMaxCoordinates.minLat, longitude: minMaxCoordinates.maxLong)
let center = CLLocationCoordinate2D(latitude: (minMaxCoordinates.maxLat + minMaxCoordinates.minLat) / 2.0, longitude: (minMaxCoordinates.maxLong + minMaxCoordinates.minLong) / 2.0)
let radiusInMeters = abs(nw.distance(from: se)) / 2.0
return MKCircle(center: center, radius: radiusInMeters)