pyPebble 0.1.0

Multi purpose N-body sim

PyPebble: An N-Body Simulation Toolkit

PyPebble is a Python model to handle N-body problems, specifically geared towards gravitational simulations (with more features planned for the future). This code is still under development. Currently, inputs and outputs are configured to use the following units:

• Distance: parsecs
• Mass: solar masses
• Time: megayears

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Installation

Using pip:

pip install pyPebble

Clone this repository and then install manually with:

pip install -e .

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Usage

Creating a System

You can define the properties of particles directly by passing arrays of positions, velocities, and masses:

from pypebble import Pebbles

system = Pebbles(positions, velocities, masses)

Alternatively, you can create a disc of particles using the built-in generator:

system = Pebbles().create_disc(
    n_particles=100,
    r_max=10,
    center=[0, 0],
    ang_vel=0.05,
    v_sigma=None,
    total_mass=None,
    particle_mass=None,
    distribution="uniform"
)

Setting up the Simulation

With a system defined, initialize the simulation using setup:

simulation = system.setup(
    softening=1e-2,
    bounds=20,
    smooth_len=10,
    t_start=0,
    t_finish=50,
    nsteps=1000,
    Enable_GPU=True,
    save_output=None
)

Live Animation

simulation.start_animation()

Running the Simulation

Run with:

simulation.run()

The simulation currently saves output data (time, position, velocity, and mass) to an .h5 file. Future improvements will include better ways to run and visualize simulations.

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To do

• Support for multiple unit systems
• Additional initial condition generators
• General Optimisations
• GUI
• Energy conservation checks
• Multiprocessing option for simulation
• Multithreading for writing to file
• Allow simulations beyond a 2D plane
• Realistic velocity and density distributions

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License

MIT License.