potamides

About

potamides is a Python package for constraining gravitational potentials using stellar stream curvature analysis. The name is inspired by Greek ποταμίδες ("potamídes", meaning "river streams"), with the initial "P" representing $\Phi$, the conventional symbol for gravitational potential in astronomy.

Key Features

• 🌊 Spline-based stream modeling: Smooth parametric representation of stellar streams with cubic spline interpolation
• 📐 Curvature analysis: Compute geometric properties including tangent vectors, curvature, principal normals, and arc-length
• 🌌 Gravitational field fitting: Match stream curvature to potential models with customizable halo and disk components
• ⚡ JAX-accelerated: Fast, GPU-compatible computations with automatic differentiation and JIT compilation
• 📊 Likelihood framework: Bayesian inference for potential parameters using curvature-acceleration alignment
• 📈 Visualization tools: Built-in plotting methods for tracks, geometry vectors, and gravitational fields

Installation

Using pip (recommended)

pip install potamides

From source

git clone https://github.com/xggs-dev/potamides.git
cd potamides
uv pip install -e .

Requirements

• Python >= 3.11
• JAX >= 0.5.3
• For GPU support, install JAX with CUDA support separately
• See pyproject.toml for full dependency list

License

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

Acknowledgments

This package builds upon excellent open-source scientific software:

• JAX: High-performance numerical computing with automatic differentiation
• galax: Galactic dynamics in JAX
• interpax: Interpolation library for JAX
• Astropy: Community Python library for astronomy
• unxt: Unitful quantities for JAX

---