Double Pendulum

A double pendulum is a pendulum with another pendulum attached to its end. This code simulates the temporal evolution of the double pendulum by solving a set of coupled ordinary differential equations (using the Runge Kutta method) with given user specified initial conditions. The rendering is done using the SDL2 library.

How To Install & Run (Linux)

1. Install the C++ compiler g++ using the following command:

sudo apt-get install g++

To check which version is installed run the following command:

g++ --version

2. Install the SDL2 library using the following command:

sudo apt install libsdl2-image-dev

3. Clone the remote repository to your local machine using the following command:

git clone https://github.com/frederic-hallein/double-pendulum

4. To compile the project, go inside the double_pendulum/ directory and run the following command:

make all

This should create a main executable file in the same directory.

5. Run the executable by using the following command:

./main

Setup

To set up custom initial conditions, simply press ENTER. This prompts the user the following variables that require custom input:

• m_1: mass 1st pendulum [unitless]
• m_2: mass 2nd pendulum [unitless]
• L_1: length 1st pendulum [unitless]
• L_2: length 2nd pendulum [unitless]
• ini_theta_1: initial angle 1st pendulum [degrees]
• ini_theta_2: initial angle 2nd pendulum [degrees]
• With friction? (y/n): air friction

To run the default initial conditions, simply run the command d. The default setup is the following:

• m_1 = 1
• m_2 = 1
• L_1 = 150
• L_2 = 150
• ini_theta_1 = 180
• ini_theta_2 = 180
• friction: no

Screencast

Screencast of the simulation running the default setup.

Screencast.from.2024-08-06.14-48-29.webm