traj-dist-rs 0.1.0a3

High-performance trajectory distance calculations in Rust with Python bindings

traj-dist-rs

A high-performance Rust implementation of trajectory distance algorithms with Python bindings, offering significant speed improvements over the original traj-dist library.

📖 About

traj-dist-rs is a high-performance trajectory distance calculation library written in Rust, providing both native Rust APIs and Python bindings via PyO3. It is a complete rewrite of the original traj-dist library, focusing on performance optimization and modern language features.

Why traj-dist-rs?

• 🚀 Performance: ~73x faster than Python implementation and ~2.7x faster than Cython implementation on average
• 🔒 Safety: Rust's memory safety guarantees eliminate common runtime errors
• 📦 Cross-platform: Supports Linux, macOS, and Windows with native binaries
• 🔗 Dual API: Use it from Python or Rust with minimal overhead
• 🎯 Accuracy: All algorithms verified against original implementation with < 1e-8 error margin

✨ Features

Supported Distance Algorithms

• SSPD - Symmetric Segment-Path Distance
• DTW - Dynamic Time Warping (with optional matrix return)
• Discret Frechet - Discrete Fréchet Distance
• Hausdorff - Hausdorff Distance
• LCSS - Longest Common Subsequence
• EDR - Edit Distance on Real sequence
• ERP - Edit distance with Real Penalty (standard & traj-dist compatible)

Distance Types

• Euclidean - 2D Euclidean distance
• Spherical - Haversine distance for geographic coordinates

Additional Features

• Matrix return for DP-based algorithms (DTW, LCSS, EDR, ERP, Discret Frechet)
• Precomputed distance matrix support for efficient batch computations
• Comprehensive error handling for invalid inputs
• Full Python type hints for better IDE support

🚀 Quick Start

Python

import traj_dist_rs
import numpy as np

# Define trajectories as list of [x, y] coordinates or numpy arrays
traj1 = [[0.0, 0.0], [1.0, 1.0], [2.0, 2.0]]
traj2 = [[0.1, 0.1], [1.1, 1.1], [2.1, 2.1]]

# Calculate SSPD distance
distance = traj_dist_rs.sspd(traj1, traj2, dist_type="euclidean")
print(f"SSPD distance: {distance}")

# Calculate DTW distance (returns DpResult with distance and optional matrix)
result = traj_dist_rs.dtw(traj1, traj2, dist_type="euclidean", use_full_matrix=False)
print(f"DTW distance: {result.distance}")

# Calculate Hausdorff distance
distance = traj_dist_rs.hausdorff(traj1, traj2, dist_type="spherical")
print(f"Hausdorff distance: {distance}")

Rust

use traj_dist_rs::distance::sspd::sspd;
use traj_dist_rs::distance::dtw::dtw;
use traj_dist_rs::distance::base::TrajectoryCalculator;
use traj_dist_rs::distance::distance_type::DistanceType;

fn main() {
    let traj1 = vec![[0.0, 0.0], [1.0, 1.0], [2.0, 2.0]];
    let traj2 = vec![[0.1, 0.1], [1.1, 1.1], [2.1, 2.1]];

    // Calculate SSPD distance
    let dist = sspd(&traj1, &traj2, DistanceType::Euclidean);
    println!("SSPD distance: {}", dist);

    // Calculate DTW distance
    let calculator = TrajectoryCalculator::new(&traj1, &traj2, DistanceType::Euclidean);
    let result = dtw(&calculator, false);
    println!("DTW distance: {}", result.distance);
}

📦 Installation

From PyPI (Python)

pip install traj-dist-rs

From Source

Prerequisites:

• Rust 1.70 or later
• Python 3.10, 3.11, 3.12, or 3.13
• maturin

Build and install:

# Clone the repository
git clone <repository-url>
cd traj-dist-rs

# Install development dependencies
pip install maturin

# Build and install in development mode
maturin develop

# Or build a release wheel
maturin build --release
pip install target/wheels/*.whl

Rust-only build:

cargo build --release

📊 Performance

Compared to the original traj-dist implementation (based on median values from K=1000 trajectory pairs):

Overall Performance

Implementation	Average Speedup
Rust vs Python	~73x faster
Rust vs Cython	~2.7x faster

By Distance Type

Euclidean Distance:

• Rust vs Python: ~389x faster (range: 187x - 595x)
• Rust vs Cython: ~10x faster (range: 6x - 16x)

Spherical Distance:

• Rust vs Python: ~76x faster (range: 41x - 167x)
• Rust vs Cython: ~2.7x faster (range: 1.6x - 5.2x)

Best Performing Algorithms

Rust vs Cython (Euclidean):

• SSPD: 16.13x faster
• Hausdorff: 14.07x faster
• ERP: 12.03x faster

Rust vs Python (Euclidean):

• DTW: 595x faster
• Discret Frechet: 554x faster
• LCSS: 381x faster

For detailed performance analysis with statistics, see docs/performance.md.

📚 Documentation

• Installation Guide: docs/installation.md
• Usage Examples: docs/usage.md
• Python API: docs/api.md
• Rust API: docs/user_guide_rust.md
• Algorithm Details: docs/algorithms.md
• Performance Report: docs/performance.md

🧪 Testing

Python Tests

cd traj-dist-rs
pip install pytest numpy polars pyarrow
pytest py_tests/

Rust Tests

cd traj-dist-rs
cargo test

Integration Tests

Run comprehensive integration tests:

bash scripts/pre_build.sh

🤝 Contributing

We welcome contributions! Please see our contributing guidelines:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Make your changes
4. Run tests and ensure they pass
5. Format your code (cargo fmt for Rust, black for Python)
6. Commit your changes (git commit -m 'Add amazing feature')
7. Push to the branch (git push origin feature/amazing-feature)
8. Open a Pull Request

Development Workflow

For daily development, use the pre-build script:

bash scripts/pre_build.sh

This script will:

• Format Rust and Python code
• Run linting (clippy, ruff)
• Run all tests (Rust + Python)
• Generate Python stub files
• Build Python bindings

🔧 Project Structure

traj-dist-rs/
├── src/
│   ├── distance/       # Distance algorithm implementations
│   ├── binding/        # Python bindings (PyO3)
│   └── lib.rs          # Library entry point
├── tests/              # Rust integration tests
├── py_tests/           # Python integration tests
├── python/             # Python package source
├── docs/               # Documentation
└── scripts/            # Build and utility scripts

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Original traj-dist library for algorithm reference
• PyO3 for Python bindings
• The Rust community for excellent tooling and libraries

📮 Support

• Issues: Report bugs and request features via GitHub Issues
• Discussions: Join discussions about usage and development
• Documentation: Check the docs directory for detailed guides

🗺️ Roadmap

For information about upcoming features and releases, see roadmap_0.1.0a1.md.

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Version: 0.1.0-alpha.1
Last Updated: 2026-02-05