Programming Project: Galaxy-Crash - Data Generation

This repository contains a Python3 script to generate simulation data for the programming project Galaxy-Crash according to https://github.com/SCTeaching-NBody/ProgrammingProject_Slides usable with https://github.com/SCTeaching-NBody/ProgrammingProject_Implementation_Cpp or https://github.com/SCTeaching-NBody/ProgrammingProject_Implementation_Java.

Dependencies

Required Python3 packages:

• dataclass_csv
• argparse

They can be installed using:

pip3 install -r requirements.txt

Usage

The script can be used to generate data sets containing a large and a small galaxy where the small galaxy orbits the larger one and crashing into it during the simulation. The RATIO determines how many of the NUM_PARTICLES are associated with the small galaxy. For example, with -n 1000 and -r 0.2, 800 particles are assigned to the large galaxy and 200 particles to the small galaxy.

python3 generate_data.py --help
usage: generate_data [-h] -o OUTPUT -n NUM_PARTICLES [-r RATIO]

Generate a data set consisting of two galaxies colliding with each other.

options:
  -h, --help            show this help message and exit
  -o OUTPUT, --output OUTPUT
                        the output filename containing the Cartesian State Vectors in CSV format
  -n NUM_PARTICLES, --num_particles NUM_PARTICLES
                        the number of particles in the data set
  -r RATIO, --ratio RATIO
                        the ratio of particles between the large and small galaxy (0.0 = all particles are located in the large galaxy)

The resulting csv file contains 8 columns:

id,mass,pos_x,pos_y,pos_z,vel_x,vel_y,vel_z

• the unique ID of the particle to identify it in the ground truth file
• the mass of the particle
• the position of the particle in the 3-dimensional space
• the velocity of the particle in the 3-dimensional space

generate.php

This PHP file can be used on a webserver allowing for generating data set with up to 200000 particles using a wget or curl call. Note: the necessary dependencies must be installed beforehand!