whirls 1.0

A fullscreen program that displays an animated, twisting tessellation of whirls

This fullscreen program displays an animated, twisting tessellation of whirls. Click to show or hide a panel of sliders to adjust the whirls. Press Esc to exit.

What is a Whirl?

Begin with an arbitrary polygon. Construct a nested polygon by joining points that are a fractional distance along each edge. Repeat this process ad infinitum.

The vertices of the whirl form a logarithmic spiral, and they approximate a pursuit curve. The center of the spiral is the centroid of the polygon.

If the constructed polygon’s vertices lie on midpoints of the base polygon, then it’s called a midpoint polygon. If the constructed polygon has an even number of sides, then it’s called a derived polygon.

Dependencies

This program was developed against:

• Python 3.5

• NumPy 1.10

• SciPy 0.17

• Matplotlib 1.5

• Pygame 1.9

• PGU 0.18

Older versions may or may not work.

Installation

These are minimal instructions to install and run this program on Windows 64 bit, including all dependencies. These instructions will not interfere with any other installed versions of Python and do not affect your PATH environment variable.

1. Download WinPython-64bit-3.5.1.3.exe and install to C:\py\WinPython-64bit-3.5.1.3

2. Download pygame-1.9.2a0-cp35-none-win_amd64.whl and pgu-0.18.zip.

3. Open Command Prompt and run the following:

   C:\py\WinPython-64bit-3.5.1.3\python-3.5.1.amd64\python -m pip install C:\Users\<user>\Downloads\pygame-1.9.2a0-cp35-none-win_amd64.whl
   C:\py\WinPython-64bit-3.5.1.3\python-3.5.1.amd64\python -m pip install C:\Users\<user>\Downloads\pgu-0.18.zip
   C:\py\WinPython-64bit-3.5.1.3\python-3.5.1.amd64\python -m pip install whirls
   C:\py\WinPython-64bit-3.5.1.3\python-3.5.1.amd64\python -m whirls