localcartesian 0.1.0

Fast GPS to local Cartesian coordinate conversion using GeographicLib

LocalCartesian

Fast GPS to local Cartesian coordinate conversion using GeographicLib.

Description

This package provides efficient conversion between GPS coordinates (latitude, longitude) and local Cartesian coordinates (x, y). It uses the GeographicLib C++ library through Python bindings created with pybind11.

The package exists because GeographicLib's Python bindings don't include the equivalent of the C++ LocalCartesian class, which is essential for many geospatial applications.

Installation

System Dependencies

Before installing, you need to have GeographicLib installed on your system:

Ubuntu/Debian:

sudo apt-get install libgeographic-dev

macOS (with Homebrew):

brew install geographiclib

Python Package

Install from PyPI:

pip install localcartesian

Or install from source:

git clone <repository-url>
cd localcartesian
pip install .

Usage

import numpy as np
from localcartesian import gps2xy, xy2gps

# Define some GPS coordinates (lat, lon pairs)
gps_coords = [
    [40.7128, -74.0060],  # New York City
    [40.7589, -73.9851],  # Times Square
    [40.6892, -74.0445],  # Statue of Liberty
]

# Define origin point (lat, lon, altitude)
origin = [40.7128, -74.0060, 0.0]  # NYC as origin

# Convert GPS to local Cartesian coordinates
local_coords = gps2xy(gps_coords, origin)
print("Local coordinates:", local_coords)

# Convert back to GPS coordinates
gps_back = xy2gps(local_coords, origin)
print("GPS coordinates:", gps_back)

API Reference

gps2xy(latlon, origin_latlonalt)

Convert GPS coordinates to local Cartesian coordinates.

Parameters:

• latlon: List of [latitude, longitude] pairs
• origin_latlonalt: Origin point as [latitude, longitude, altitude]

Returns:

• List of [x, y] coordinate pairs in meters

xy2gps(xy, origin_latlonalt)

Convert local Cartesian coordinates to GPS coordinates.

Parameters:

• xy: List of [x, y] coordinate pairs in meters
• origin_latlonalt: Origin point as [latitude, longitude, altitude]

Returns:

• List of [latitude, longitude] pairs

Development

Building from Source

Requirements:

• C++11 compatible compiler
• GeographicLib development headers
• pybind11
• Python development headers

# Install build dependencies
pip install pybind11 setuptools wheel

# Build and install
pip install .

# For development installation
pip install -e .

Running Tests

pip install pytest
pytest tests/

License

This project is licensed under the MIT License.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.