# Geospatial Metrics

> NumKong for Go

The Go package also exposes Haversine and Vincenty helpers, from every point of one set to every point of another.
Inputs are in radians.
Outputs are written into caller-owned slices, one row of distances per point of the first set.

```go
package main

import (
	"fmt"

	nk "github.com/ashvardanian/NumKong/golang"
)

func main() {
	// Statue of Liberty (40.6892°N, 74.0445°W) → Big Ben (51.5007°N, 0.1246°W)
	libertyLatitudes := []float64{0.7101605100}
	libertyLongitudes := []float64{-1.2923203180}
	bigBenLatitudes := []float64{0.8988567821}
	bigBenLongitudes := []float64{-0.0021746802}
	distances := make([]float64, 1)

	nk.VincentysF64(libertyLatitudes, libertyLongitudes, bigBenLatitudes, bigBenLongitudes, distances)  // ≈ 5,589,857 m on WGS-84
	nk.HaversinesF64(libertyLatitudes, libertyLongitudes, bigBenLatitudes, bigBenLongitudes, distances) // ≈ 5,574,848 m on the mean sphere

	fmt.Println(distances[0])
}
```

The output slice is caller-owned.
That keeps allocation behavior explicit and predictable.

`import "github.com/ashvardanian/NumKong"`

## HaversinesF64

HaversinesF64 writes the great-circle distance in meters from each a point to each b point, with float64 coordinates in radians, into results, row-major with len(bLatitudes) columns.

```go
func HaversinesF64(
    aLatitudes, aLongitudes, bLatitudes, bLongitudes, results []float64,
)
```

Each latitude slice matches its longitude slice, and results holds len(aLatitudes) * len(bLatitudes) entries.

## VincentysF64

VincentysF64 writes the ellipsoidal geodesic distance in meters from each a point to each b point, with float64 coordinates in radians, into results, row-major with len(bLatitudes) columns.

```go
func VincentysF64(
    aLatitudes, aLongitudes, bLatitudes, bLongitudes, results []float64,
)
```

Each latitude slice matches its longitude slice, and results holds len(aLatitudes) * len(bLatitudes) entries.