typealias NumKongGeospatial = NumKongHaversines & NumKongVincentysThe Swift geospatial helpers operate on four coordinate arrays, two per point set. They score every point of the first set against every point of the second. Inputs are in radians. Outputs are in meters, row-major with one row per point of the first set.
import NumKong
// Statue of Liberty (40.6892°N, 74.0445°W) → Big Ben (51.5007°N, 0.1246°W)
let libertyLatitudes: [Float64] = [0.7101605100]
let libertyLongitudes: [Float64] = [-1.2923203180]
let bigBenLatitudes: [Float64] = [0.8988567821]
let bigBenLongitudes: [Float64] = [-0.0021746802]
let ellipsoidal = vincentys(
aLatitudes: libertyLatitudes, aLongitudes: libertyLongitudes,
bLatitudes: bigBenLatitudes, bLongitudes: bigBenLongitudes) // ≈ [5,589,857] m
let spherical = haversines(
aLatitudes: libertyLatitudes, aLongitudes: libertyLongitudes,
bLatitudes: bigBenLatitudes, bLongitudes: bigBenLongitudes) // ≈ [5,574,848] mThe low-level UnsafeBufferPointer static methods on Float64 remain available for zero-copy use cases.
API
Types
NumKongGeospatialConvenience alias for types supporting both Haversine and Vincenty geospatial distances.
ProtocolNumKongHaversinesA type that can compute SIMD-accelerated great-circle Haversine distances from every point of one set to every point of another, row-major with one row per a point.1
protocol NumKongHaversines : BinaryFloatingPointConforms to
BinaryFloatingPoint, ExpressibleByFloatLiteral, FloatingPoint, Hashable, Equatable, Strideable, Comparable, SignedNumeric, Numeric, ExpressibleByIntegerLiteral, AdditiveArithmeticConforming types
haversinesWrites Haversine distances from every a point to every b point into results.
static func haversines(
aLatitudes: UnsafeBufferPointer<Self>,
aLongitudes: UnsafeBufferPointer<Self>,
bLatitudes: UnsafeBufferPointer<Self>,
bLongitudes: UnsafeBufferPointer<Self>,
results: UnsafeMutableBufferPointer<Self>
) -> Boolstatic func haversines<A, B, C, D>(
aLatitudes: A,
aLongitudes: B,
bLatitudes: C,
bLongitudes: D
) -> [Self]? where Self == A.Element, A : Sequence, B : Sequence, C : Sequence, D : Sequence, A.Element == B.Element, B.Element == C.Element, C.Element == D.ElementComputes Haversine distances from every a point to every b point.
Coordinates are in radians, with as many longitudes as latitudes in each set.
results receives meters, row-major with one row per a point.
Returns
false if a set is empty or its coordinate counts differ, if results does not hold one value per pair, or if a kernel reports an error.ProtocolNumKongVincentysA type that can compute SIMD-accelerated Vincenty ellipsoidal geodesic distances from every point of one set to every point of another, row-major with one row per a point.1
protocol NumKongVincentys : BinaryFloatingPointConforms to
BinaryFloatingPoint, ExpressibleByFloatLiteral, FloatingPoint, Hashable, Equatable, Strideable, Comparable, SignedNumeric, Numeric, ExpressibleByIntegerLiteral, AdditiveArithmeticConforming types
vincentysWrites Vincenty geodesic distances from every a point to every b point into results.
static func vincentys(
aLatitudes: UnsafeBufferPointer<Self>,
aLongitudes: UnsafeBufferPointer<Self>,
bLatitudes: UnsafeBufferPointer<Self>,
bLongitudes: UnsafeBufferPointer<Self>,
results: UnsafeMutableBufferPointer<Self>
) -> Boolstatic func vincentys<A, B, C, D>(
aLatitudes: A,
aLongitudes: B,
bLatitudes: C,
bLongitudes: D
) -> [Self]? where Self == A.Element, A : Sequence, B : Sequence, C : Sequence, D : Sequence, A.Element == B.Element, B.Element == C.Element, C.Element == D.ElementComputes Vincenty geodesic distances from every a point to every b point.
Coordinates are in radians, with as many longitudes as latitudes in each set.
results receives meters, row-major with one row per a point.
Returns
false if a set is empty or its coordinate counts differ, if results does not hold one value per pair, or if a kernel reports an error.Functions
*× 2
func haversines<A>(
aLatitudes: A,
aLongitudes: A,
bLatitudes: A,
bLongitudes: A
) -> [Float64]? where A : Sequence, A.Element == Double| Symbol |
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haversines |
vincentys |