ConwayLife.com

To Bullet51, x = 262, y = 66, rule = B3/S23 2$4bo249bo$4bo249bo$3bobo8b3o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o 4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b2o4b2o5b 2o4b2o5b2o4b2o5b2o4b2o5b2o4b3o8bobo$9bobob2o2bo2bo2bo3bo2bo2bo2bo3bo2b o2bo2bo3bo2bo2bo2bo3bo2bo2bo2bo3bo2bo2bo2bo3...

I am including the source code for my latest search program "knightt". I wrote this program to investigate the complete spaceship trees for spaceships of a given speed, period, and symmetry. As part of the run the smallest ship containing each unique (2*PERIOD + 1) phases of a row that is in any shi...

Matthias, On a somewhat unrelated note, you mentioned here that you had found some small c/4 orthogonal ships. Were any of those new? Here is the last posting I saw that you made of small c/4 ships with 9 added ships (60, 64x3, 65, 66, 67x2, 69). I noticed that the sombrero ones were part of some of...

Recently I have been headed in new directions in spaceship search program writing. First though, here are some spaceships I have found interesting: x = 57, y = 56, rule = B3/S23 $8bo5bo19b2o3bo5bo3b2o$6b4o3b4o15bo3bobobo3bobobo3bo$5b2o3bobo3b2o14bo 3bo4bobo4bo3bo$4bo13bo13b4o2b2obobob2o2b4o$5b2o4bo4...

Congratulations zdr! It is quite rare that someone finds a spaceship of a new speed. I think it is even rarer that someone writes their own spaceship search program. I wrote a spaceship search program back in 1995 and emailed Alan Hensel with some of my results. That is how I got involved in the lif...

I like the new thread. It is more convenient, as I have a variety of stuff. I did some more 4c/10 glide symmetric searches. At width 17 there are no period 10 ships with a period 10 front row. There are many period 5 tags to sift through in hopes of finding period 10 extensions. I checked a lot of t...

Chopping a job up in knight2 and distributing it across several scalar CPUs Over the years I have primarily used UNIX head, tail, and cat to chop jobs up. This was highly manual but workable. Under DOS this is way too much of a pain. So last weekend I modified a few lines of code in knight2.c to ma...

Sokwe, I wondered if this was possible when you first described knight2. Could this be generalized to higher numbers? If so, do you think it would continue to give performance increases? The farther the phases are apart, the faster the ship goes. For example, a ship with 3 knight3 full phases would ...

I have some negative results to report. I do not have access to the final partials right now. 2c/7 odd symmetric width 19 - no ships found, longest partial - ~300 knight2 phases, length ~75 3c/7 asymmetric width 14 - no ships found, longest partial - 90 knight3 phases, length ~30 3c/6 asymmetric wid...

Codeholic, I would run searches and produce giant armadas of 2c/4 ships. I would tend to run them then and blow them up. One time the period 16 smoker emerged after trimming the tail of some ship. It was basically total luck. Wildmyron, The problem with the width 16 2c/6 searches is they always miss...

Sokwe,

When knight2 is instructed to search (1,0)/6 or (1,1)/6 is will indeed be operating at period 8 internally. Knight2 functions fine at this setting.

-Tim Coe

Sokwe, Thanks for trying out knight2. This is going to be a learning experience for me in that I often leave out key information. When the "-v" option is used the internal period is 2 higher than the command line period for algorithmic reasons. So "-p 8 -v" is operating at an internal period of 10 a...

Scorbie, I have run many searches over the years and I have noted that for almost any search as I increase the width the final partials get very long (5 to 10 times the width) at the widths just below where ships start being found. The c/5 diagonal search at width 13 ran 400 hours before it found th...

I have several results to report: Width 15 period 6 knightship (2,1)/6 -- No ships found The longest extension that occurred was ~42 rows long of which the search program reported 37 rows. This is more encouraging than the width 11-14 results, but means to me that unless incredible luck occurs no pe...

Scorbie, Yes, I am Tim Coe. If I do a run of "knight2" and nothing is found, no spaceships exist under those run parameters (barring bugs of course). If a spaceship is found I always do some tree trimming. This will always preclude finding some other spaceships. This is a real problem when searching...

Towerator, As near as I can tell a single core today is 30 to 50 times as fast as a Pentium-90 from 20 years ago. Cores have hardly gotten faster at all over the last 10 years. There are of course many more CPU cores around. Scorbie, The (n-1)/(2n) I mentioned in the other thread does apply to knigh...

Sokwe, Alas, I cannot confirm that no 2c/6 symmetric ships exist for width 16. The following turtle tag is the problem. It repeats, it has two hookups to the turtle, and it has at least 15 completions. It completely gunks up my search tree and I cannot tell if it is masking period 6 results. I belie...

This seems to be the place to report negative results. After 20 years I decided to take another go at finding a period 6 knightship. I had an idea for a constraint propagation algorithm that would be significantly faster than my old algorithm for searches. So I gutted "knight" and started writing "k...

My new search program is designed to work at speeds in the height direction of (n-1)/(2n). It works at degraded performance at slower speeds and doesn't work at faster speeds at all. 2c/6 is the sweet spot. I did an even symmetry search at width 18 and found the following turtle tag with a small per...

I came up with a slick idea for a constraint propagation algorithm for spaceship searches. So I gutted my 20 year old search program "knight" and started writing "knight2" three weeks ago. I used c/4 searches as my initial debug test. I have found the following small c/4 ships of pip counts 41, 48, ...