An on-line implementation of quadrellation, using a square grid and Rule 105, and where the user has the ability to set up the initial conditions for the 1st row. The term quadrellation, invented by my friend Leo Marcus, refers to the process of taking a grid, copying the cells underlaying the inverted right isosceles triangle whose base is the top of the grid, and then rotating and pasting the cells in the triangle, clockwise around its apex, in three 90° increments, resulting in a square grid with 4-way symmetry. The result looks best when the grid has an odd number of columns (cells across the top) and the grid pattern is symmetrical left to right. The 1st row consists of corner cells, random cells, middle cells, an optional center cell, and then on the right, mirror copies of the middle, random, and corner cells. (There are also edge cells that can be fed into the pattern.) The user can adjust the initial condition of the 1st row by adding or deleting from any of these groups of cells. Before each quadrellation is computed, all random cells are chosen and mirrored.
An open-source implementation of the Wolfram Elementary Cellular Automaton, written in Perl, freely available for anyone to download and use. It generates JPEG (by default) or GIF images of its results, and is packaged as a ZIP file containing the Perl script and some support files and directories. The Perl implementation is command-line-driven and is much faster than the on-line calculator, but requires more expertise from the end-user. For instance, Perl must be installed, and also the Perl modules GD::Simple, File::Compare and File::Copy. (To get started, run the Perl script with the "-h" option, which prints out detailed usage information, or run it using only the "test" option.)
I am continually updating and improving these programs, which I use to find new patterns for my art. I prefer the Wolfrule Perl Calculator, because it generates JPEG or GIF images of the computed patterns, to any desired scale, which I can print out. Also, there are numerous options for manipulating the computed patterns, including colorization, filtering, selective erasing, sub-image extraction, padding, flipping (horizontal or vertical), mirroring (horizontal, vertical, 45 degrees), rotating, quadrellation (this term, and seemingly new word, courtesy of friend Leo Marcus), and many others. I've spent hundreds of hours working on and using the Wolfrule Perl Calculator, and to date I've generated tens of thousands of distinct patterns. Computer programming and pattern discovery is, for me, a very satisfying part of the artistic process.
Personal Note: I am convinced that current patent laws are unjust and that software should not be patentable. All software I write on my own time is made freely available for use by others. I'm a big supporter of GNU, I've used Emacs for over 30 years now, and I first installed Linux on a PC back in '92. I really appreciate the work being done by Creative Commons, the Electronic Frontier Foundation, and the Free Software Foundation, and I have ultimate respect and admiration for copyfighters like Richard Stallman and Cory Doctorow.