Thursday, February 23, 2017

Langton's Ant, Part 1

Good news is that a full simulation routine, written in C, and running under Linux is working. As a validation test for my coding I successfully ran Langton’s Ant, the results were animated, a video made, and posted to YouTube. 



The first pass of my simulation routine used Ncurses for text graphics display.

After I had debugged my code using a simple text graphics display, I redid the code to generate binary output data-files. Those files were in turn converted into bitmap graphic file format using a program I’ve written in LabVIEW. Lastly, with those files in turn, I could then animate using the software package Frames.

Frames might not be the best way to generate animations, but it was left over from our family’s home-schooling days when my son was working with stop motion animation. It’s a frustrating package to use, but I have it and it works… if you’re patient enough. After the animation was done, the actual video was put together using Adobe Premier Elements: version 9. Again, a software package left over from my son’s home-schooling days.

The actual simulation program was running 2 weeks ago, but it took me a week of messing around to get the animation sequence into a form I was satisfied with. I haven’t used these animation tools in five years. It took several days just for me to get back up to speed with using my old software.

The next step for me and this project is to create a Langton’s Ant program that starts out already in its stable “highway” configuration. Since the “highway” is a 104 step repeating pattern, one would expect that there will be countless ways to seed a Langton’s Ant program in this way. The question though, is there a minimal set? Or is that even a meaningful question? The next step in this direction is to recast Langton’s Ant as a two-dimensional Turing machine and analyze the system from that point of view.

For anyone finding this blog via the YouTube video post, I think I should emphasize again that Langton’s Ant is not my goal. My interests are in the underlying hardware that it will take to create a large asynchronous array of simple processors. I’m just using Langton’s Ant at this point as a simple and accessible test example.

I have recently come across the work of Dave Ackley. I’ve watched all of his posted YouTube videos and have downloaded a couple of his published papers. This paper in particular is what I’m working through right now: “A Movable Architecture for Robust Spatial Computing”, David H. Ackley*, Daniel C. Cannon and Lance R. Williams  If this is any indication, I have a lot of work ahead to catch up to the current state of the art in this field.

One way to characterize this project of mine is to see it as trying to develop the underlying silicon hardware, FPGA or ASIC, that you would need to re-create in hardware what Professor Ackley is trying to do in software. But I can’t speak for him about that. Maybe someday I’ll have a chance to talk to him and find out. 




On the more academic side, I’m steadily working my way through Hamilton’s book. I’m struggling a little more with the video lecture series; mostly because I find it very hard to sit still and watch them on the computer screen. It’s clear my brain has gotten pretty rusty over the last 25 years since I left grad school. My goal at this point is, over the next six months, to come up to speed on Turing machines and all the mathematics that goes behind them.

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