A simple simulation of a group of particles in a box, with electromagnetic interactions. As an output you will get two files, a png with the first and last state, and a gif with the temporal evolution.

• Python3
• Gnuplot

You will need a bash or other UNIX-based terminal for running the following commands. However, you can run the simulation by hand by running main.py, and then, by running PlotCopy.gp.

Download the latest release from releases.

Then extract the source code. Open a terminal on the PyColloid folder and then just execute the shell script RUN.sh by typing:

./RUN.sh

Ideally you will get a terminal output like this:

Case: [Low/High]APF
[n] frames in animation sequence

But most likely you will have some: Collision loop exceeded for this particle. Which means that you will have overlaps between particles in the animation. You can try minimizing this by putting a higher value on CollisionLoops (see the next list), but you will increase the computation time. Other method is to play with the DeltaTime, MaxVo and ForceConstant parameters, this will not add computation time, but change the whole simulation environment.

You can change the parameters of the simulation by changing the Parameters.txt file. This file its by itself very self-explanatory but here is a bit of documentation:

• Case: Select the method of sorting the initial state by choosing the scenario HighAPF (high atomic packing factor), or LowAPF (low atomic packing factor).
• APF: Set a fixed APF, this will rewrite the number of particles, you can turn it off by tying -1.
• Particles: Number of particles on the simulation.
• Mass: Mass of each particle.
• MaxCharge: Maximum charge of each particle.
• MinCharge: Minimum charge of each particle.
• MaxRadius: Maximum radius of each particle.
• MinRadius: Minimum radius of each particle.
• MaxX: x length of the box.
• MinY: y length of the box.
• MaxVo: Maximum initial velocity in any direction for the particles.
• ForceConstant: Parameter k used on Coulumb's law.
• DeltaTime: Time of each evolving interval.
• Iterations: Total of DeltaTime iterated.
• CollisionLoops: Maximum iterations for calculating a collision.
• Palette: Palette used for coloring the charge, you can use any of the ones listed here.
• Invert: Invert the palette on plot.

Finally, you can change some parameters and re-plot without having to re-simulate by simply typing:

./RePlot.sh

Remember you can choose the palette of your choice from this list:

• Improve collision dynamics.
• Program InitialValues.py
• Program TemporalEvolution.py
• Program CollisionDetector.py
• Program CollisionDynamics.py
• Program main.py
• Program the plotter base
• Finish the plotter