GeoDecode

GeoDecode is a Go package that provides offline reverse geocoding. It allows you to find the nearest city and country for a given latitude and longitude coordinate.

What it Does

This package takes a geographic coordinate (latitude and longitude) and returns the name of the closest known city and its country code. It's designed for quick lookups using an embedded dataset.

Features

• Offline Reverse Geocoding: Works without an internet connection after initial setup.

• City and Country Lookup: Provides the name of the nearest city and its ISO Alpha-2 country code.

• Fast Lookups: Uses a KD-Tree for efficient nearest neighbor searches on a large dataset.

• Embedded Data: The necessary geographic data is bundled directly into the package.

Installation

To use GeoDecode in your Go project, you can install it using go get:

go get github.com/sdwillbrand/GeoDecode

Usage

Here's a simple example of how to use GeoDecode in your Go application:

package main

import (
  "fmt"
  "github.com/sdwillbrand/GeoDecode" // Import the GeoDecode package
)

func main() {
  // Define a coordinate (e.g., Berlin, Germany)
  coords := [2]float64{52.5200, 13.4050} // [lat, lng]

  // Find the nearest location.
  // The 'true' argument enables verbose logging during the initial data load.
  location := geodecode.FindLocation(coords, true)

  if location != nil {
    fmt.Printf("Found Location:\n")
    fmt.Printf("  City: %s\n", location.City)
    fmt.Printf("  Country Code: %s\n", location.CC)
    fmt.Printf("  Latitude: %.5f, Longitude: %.5f\n", location.Lat, location.Lon)
  } else {
    fmt.Println("Location not found for the given coordinates.")
  }

   // Example with an ocean coordinate (will return the nearest land location)
   oceanCoords := [2]float64{0.0, 0.0}
   oceanLocation := geodecode.FindLocation(oceanCoords, false) // No verbose logging for subsequent calls

  if oceanLocation != nil {
    fmt.Printf("\nClosest to ocean (0,0):\n")
    fmt.Printf("  City: %s\n", oceanLocation.City)
    fmt.Printf("  Country Code: %s\n", oceanLocation.CC)
  }
}

Data Source

The geographic data used by GeoDecode is sourced from rg_cities1000.csv. This CSV file contains a list of cities with their coordinates and administrative information. The file is embedded directly into the Go package for ease of use.

Contributing

If you find issues or have suggestions, please open an issue on the GitHub repository.

License

GeoDecode is free and open source project licensed under the MIT License.