## #17 reflect both axes

open
nobody
None
5
2009-12-04
2009-12-04
Zom-B
No

I'm requesting a new symmetry mode in the .table file format for simultaneous X and Y reflectivity, so that

1,0,3,3,0,0,0,0,0,2
1,0,0,3,3,0,0,0,0,2
1,0,0,0,0,0,3,3,0,2
1,3,0,0,0,0,0,3,3,2

can be written as

1,0,3,3,0,0,0,0,0,2

rather than this, using "reflect" symmetry

1,0,3,3,0,0,0,0,0,2
1,0,0,0,0,0,3,3,0,2

It might be called something in the lines of "reflectXY" or "reflect4".

And possibly another symmetry, "reflectY" for vertical reflectivity as "reflect" appears to reflect horizontally only (determined experimentally; there is no description in the help).

## Discussion

• Andrew Trevorrow - 2009-12-05

Probably better to discuss these ideas at the Rule Table Repository:

Personally, I'm no longer all that interested in the .table format now
that Tim Hutton has written make-ruletree.py (available in Golly 2.2
makes it easy to create a new rule (as a .tree file) by writing a
suitable transition function in Python. See the simple examples
at the top of the script. Such functions are pretty easy to write --
you don't have to know much Python -- and they are a lot easier
to understand than the somewhat inscrutable .table format.

You write the transition function in your favorite text editor, copy
it to the clipboard, switch to Golly and run make-ruletree.py.
The script grabs your code from the clipboard and uses it to
create a .tree file, installs it in your rules folder and switches to
the new rule. Very neat.

• Nobody/Anonymous - 2009-12-06

Thanks, After your suggestion I found a Java program included with Golly to make ruletrees. As I don't know much Python, but a lot of Java, I thought I'd give this a shot first. However, after starting out with my transition function, an automaton of 25 states and 8 directions, I noticed it would take 10 days on my computer to finish.

I dug into the code and optimized it using the same basic techniques I always use and to my surprise it became 200 times faster! After some more fiddling around It became another 2 times faster, making it 400 times faster than the original!!

Now it will only take 35 minutes to finish.

The code is here:
http://www.darkwired.nl/~zombie/RuleTreeGenOptimized.java

• Zom-B - 2009-12-06

(why wasn't I logged in?)

I need to correct myself a bit. It felt like it was too good to be true. I accidentally entered 15 states instead of 25. With 25 states, it's still a 4.3 times faster than the original though.

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