commensurability: a Python package for classifying astronomical orbits based on their toroid volume
arXiv:2505.10617 · doi:10.21105/joss.07009
Abstract
As a star orbits the center of its host galaxy, the trajectory is encompassed within a 3D toroid. The orbit probes all points in this toroid, unless its orbital frequencies exhibit integer ratios (commensurate frequencies), in which case a small sub-volume is traversed. commensurability is a Python package that implements a tessellation-based algorithm for identifying orbital families that satisfy commensurabilities by measuring the toroid volume traversed over orbit integration. Compared to standard orbit classification methods such as frequency analysis, tessellation analysis relies on configuration space properties alone, making classification results more robust to frequency instabilities or limited integration times. The package provides a framework for analyzing phase-space coordinates using tessellation analysis, including a subpackage for the implementation of the general tessellation algorithm. The package is to be used with a galactic dynamics library; it currently supports AGAMA, gala, and galpy.
5 pages and 1 figure. Published to the Journal of Open Source Software (JOSS). Software repository: https://github.com/ilikecubesnstuff/commensurability
References in corpus (6)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
- galpy: A Python Library for Galactic Dynamics
- AGAMA: Action-based galaxy modelling architecture
- Using Commensurabilities and Orbit Structure to Understand Barred Galaxy Evolution
- Orbital support and evolution of flat profiles of bars (shoulders)