This is a sample application written with Angular (with Angular Material and RxJS) and a simple canvas rendering. It provides a basic demonstration of a N-Body simulation using the Barnes-Hut algorithm.
The Barnes-Hut Simulation is an approximation algorithm that can reduce the time complexity of a n-body simulation at the expense of accuracy. It accomplishes this by breaking space into quadrants (octants in 3D) and reducing each quad into new nodes until only one body occupies a qaud. The forces are then approximated by using the center of mass (CoM) for a quad if it is sufficiently far away.
Sufficiently far is defined by the parameter θ which represents the ratio of quadrant-length over distance between target bodies (either body-body or body-CoM). A θ value of zero is worse than the brute-force approach incurring tree construction penalties too. A θ value of one provides good performance with small error. Higher values incur higher error and faster run-time.
(https://en.wikipedia.org/wiki/Barnes%E2%80%93Hut_simulation)
- Execute
npm start - Open
localhost:4200in a browser
Within the application you can:
- Adjust the number of bodies.
- Change the value of θ. High values are less accurate, but more preferment. Low values are more accurate. A value of 1 others a decent compromise.
- Change the value Δt.
- Click on any body to see it's details
- Position, velocity, force, and rendering options
- Implement E2E
- Implement component/unit tests
- Implement body generators and drop down selector
- Random generator
- User defined bodies
- Pre-configured scenes, e.g. stable orbits, etc
- Separate canvas rendering logic from simulation logic (visitor pattern similar approach)
- Body
- BarnesHutNode
- Boundary
- Move simulation calculation loop to WebHelper
- Test the overhead of messaging between threads
- Switch to drawing library (abstract out canvas/WebGL support), e.g. two.js or similar
- Implement better integration method
- Leap-frog
- Runge-Kutta
- Implement D3 charts for error growth vs. θ value.