🌌 GalacticPotentials.jl

An extension of ModelingToolkit.jl which provides common galactic potentials.

Installation

Choose one of the two lines below!

Pkg.add("GalacticPotentials.jl")    # in Julia code

pkg> GalacticPotentials             # in Julia's REPL

Usage

Potentials are defined as subtypes of ModelingToolkit.jl models. They can be converted to ODESystem and ODEProblem types to interact with the rest of the SciML ecosystem.

using Plots
using ModelingToolkit
using DifferentialEquations
using GalacticPotentials

let model = PlummerPotential(gradient=true)

    p = @nonamespace Dict(
        model.G => 6.6743e-20, # field strength (km³ kg⁻¹ s⁻²)
        model.m => 6e31,       # mass (kg)
        model.b => 1e-6        # softening parameter (unitless)
    )

    u0 = @nonamespace Dict(
        model.x => 11e5,
        model.y => 5e5,
        model.z => 0,
        model.ẋ => 1e3,
        model.ẏ => 1e3,
        model.ż => 0
    )

    ts = (0.0, 1e6)

    problem = ODEProblem(model, u0, ts, p)
    solution = solve(problem; reltol=1e-14, abstol=1e-14)

    plot(solution; idxs=(:x,:y), label=:none, dpi = 400, aspect_ratio=:equal)
end

Credits

This package is bootstrapped off of gala and galpy, two rich Python packages for galactic dynamics. I aim to learn about galactic dynamics by integrating the models within these two popular Python packages into the SciML ecosystem. The Gala and GalPy licenses are shown below.

Gala License

The MIT License (MIT)

Copyright (c) 2012-2024 Adrian M. Price-Whelan

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

GalPy License

Copyright (c) 2010, Jo Bovy
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its
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this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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