Thread for basic questions

[bubblegum]

what is salt?(talking about CA)

The salt Saka collects?

[Hunting]

I knowvI've been asking short questions a lot recently, but I'm not dvgrn.

Why does LeapLife glider eaters so specialized that they can hardly catalyze anything except gliders? I have quite a few glider eaters from dr now, but unlike Life (where eater 1, eater 2, and many in the eater stamp collection can catalyze many things with the pre-block head) they are of unbelievably limited use.

[mniemiec]

Why does LeapLife glider eaters so specialized that they can hardly catalyze anything except gliders? I have quite a few glider eaters from dr now, but unlike Life (where eater 1, eater 2, and many in the eater stamp collection can catalyze many things with the pre-block head) they are of unbelievably limited use.

That's easy. Rule B2n means that gliders (or other expanding patterns) in LeapLife tend to attack other objects the generation before they can form a line of two, which is the usual way that most eaters eat (i.e. a line of 2 on the glider/target + line of 2 on the eater form two new births, which overwhelm both the eater and the target; the eater reforms, but the target does not). As a result, the kinds of things that eat gliders in this rule have to be constructed totally differently (and eat totally differently) from most Life eaters. This also makes creating converter mechanisms much harder in this rule.

[yujh]

what is salt?(talking about CA)

The salt Saka collects?

Yes

[Hunting]

Why does LeapLife glider eaters so specialized that they can hardly catalyze anything except gliders? I have quite a few glider eaters from dr now, but unlike Life (where eater 1, eater 2, and many in the eater stamp collection can catalyze many things with the pre-block head) they are of unbelievably limited use.

That's easy. Rule B2n means that gliders (or other expanding patterns) in LeapLife tend to attack other objects the generation before they can form a line of two, which is the usual way that most eaters eat (i.e. a line of 2 on the glider/target + line of 2 on the eater form two new births, which overwhelm both the eater and the target; the eater reforms, but the target does not). As a result, the kinds of things that eat gliders in this rule have to be constructed totally differently (and eat totally differently) from most Life eaters. This also makes creating converter mechanisms much harder in this rule.

Ah - thanks for explaining. There's another angle where a glider can approach an SL though without using B2n, so I'll try it...

[wildmyron]

Ok sorry for asking this again. (At least I know more this time.) I'm having trouble compiling. Yesterday I downloaded Microsoft Visual C++ 2008 Express Edition and followed this tutorial. I tried compiling ofind, and I got this:

Code: Select all

c:\ofind>cl ofind.c
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86
Copyright (C) Microsoft Corporation.  All rights reserved.

ofind.c
Microsoft (R) Incremental Linker Version 9.00.30729.01
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:ofind.exe
ofind.obj
ofind.obj : error LNK2019: unresolved external symbol _random referenced in function _initHash
ofind.exe : fatal error LNK1120: 1 unresolved externals

Is this a simple programming error or something else?

This is really just related to differences in libs included with the compiler / dev environment for different compilers. To compile ofind with cl.exe just change the two function calls of "random" to "rand". In my local copy I also increased STATE_SPACE_SIZE, but it's so long ago since I tested that that I don't remember if it had any effect (I think it was to avoid ofind giving an error about the queue being full for wider searches). There are also other quirks and bugs in ofind, but it can still be used to get some good results.

ofind will probably run a bit faster if you compile with

Code: Select all

cl /O2 ofind.c

Make sure you are compiling from the "x86 Native Tools for Visual Studio" command prompt rather than just opening the command prompt directly. This ensures the dev environment is set up properly.

After compiling you can run it by simply typing "ofind" at any cmd prompt.

Also, that's an ancient version of MSVC. Why not get the current version? I just tested compiling ofind with the above change using MSVC 2019 Community Edition.

I tried compiling dr too and got this:

Code: Select all

Setting environment for using Microsoft Visual Studio 2008 x86 tools.

C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC>cd c:\

c:\>cd c:\dr

c:\dr>dir
 Volume in drive C has no label.
 Volume Serial Number is 682F-393C

 Directory of c:\dr

02/16/2021  07:43 PM    <DIR>          .
02/16/2021  07:43 PM    <DIR>          ..
               0 File(s)              0 bytes
               2 Dir(s)  269,769,011,200 bytes free

c:\dr>cl dr.c
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86
Copyright (C) Microsoft Corporation.  All rights reserved.

dr.c
c1 : fatal error C1083: Cannot open source file: 'dr.c': No such file or directory

Did I not select it properly? It's in a zip file, if that helps in any way.

The directory you are trying to compile in is empty which is why you get the error "Cannot open source file: 'dr.c': No such file or directory".
Make sure you extract the zip file first and ensure you have all the required files in the current working directory.

Also, I know that the LifeWIki compiling tutorial uses Cygwin, but AFAIK that tutorial is outdated, so I didn't use it.

It might be slightly out of date but it's still got useful info.

Yesterday I downloaded Microsoft Visual C++ 2008 Express Edition

WHY WOULD YOU WANT THAT FOR COMPILING ANYWAYS? Plain gcc is good.

That's not very helpful. There are several good reasons to compile with MSVC, not least that you can run the resulting executable on any other Windows box without having to install anything.

@Schiaparelliorbust Any of the various options mentioned so far are reasonable. The nice thing about using gcc is that lots of CA tools (particularly the more recent ones) will compile with gcc without any change. The annoying thing about gcc is that it takes a bit to get working on Windows. Using Cygwin or Linux (under WSL/WSL2) gives you a good dev environment with all the tools you might need, but it does take a bit of getting used to. mingw64 is also readily usable, but again takes a bit to get set up and a while to get used to. Once you pick one of these and use it regularly it won't take long before you get the hang of compiling new software with it. (NOTE: if you want to compile apgsearch you'll need to use something other than MSVC because it only supports being compiled with gcc or clang.

[bubblegum]

Yes

That's a term for ships/oscs made up of singular cells staying separate in LtL rules. They look weird. Saka has a lot of them.

[C28]

what is the name of the constellation formed by this reaction?

Code: Select all

x = 7, y = 9, rule = B3/S23
b2o$o2bo$3bo$3o3$4b3o$4bobo$4bobo!

[cvojan]

I think it’s just the ash of Octomino II

[Donald K Trump]

What does Befunge glider mean?
ColorfulGalaxy doesn't seem to be a Lifenthusiast any more, because he seems to be more interested in "Befunge" and other codes than Conway's Life.
He hasn't been editing the Wiki for days.

Has ColorfulGalaxy posted any Stamp Collections? If yes, Are there any examples?
What about glider soups?

Also for the above soup, I suspect that ColorfulGalaxy has already asked about the same thing. They say that it has been rediscovered many times and needed a name.

Edit: What is gosperize?

[hotdogPi]

What does Befunge glider mean?
ColorfulGalaxy doesn't seem to be a Lifenthusiast any more, because he seems to be more interested in "Befunge" and other codes than Conway's Life.
He hasn't been editing the Wiki for days.

It's a quine: it works in both LifeViewer and an actual programming language. It's not an OCA.

[praosylen]

post

It's a quine: it works in both LifeViewer and an actual programming language. It's not an OCA.

That's not exactly a quine — a quine is typically a program in some language that prints the original program's source code when run. I think the word you're looking for is "polyglot". (In colloquial usage polyglot programs aren't always required to run identically in all languages involved, but simply function/perform some task in each of multiple different languages, contrary to the wikipedia article.)

[otismo]

What currently holds the record for being the RAREST CGoL Object ever found in a soup ?

Thank You !

Cheers !

[MathAndCode]

What currently holds the record for being the RAREST CGoL Object ever found in a soup ?

I'm sure that there are many objects that have only been found in soups once. However, this object was formed in a soup but did not survive until the end and is therefore listed in Catagolue as appearing in zero soups, so, in a way, it has been found in a soup but is rarer than objects that have only appeared in soups once. There are probably other rare objects for which the same thing has occurred, but most aren't lucky enough to be converted to a similar rare object instead of completely destroyed.

[dvgrn]

What currently holds the record for being the RAREST CGoL Object ever found in a soup ?

How do you measure relative rarity? One of the few reasonable ways to do it would be to run a whole lot of soups, and look at the censuses to see which objects show up more or less often.

But that doesn't give us any kind of plausible way to choose a "rarest CGoL object". Like, which of these two period-7 objects is rarer? There's exactly one G1 soup that produces each of them. We won't have any idea which one is rarer until some future soup produces one or the other of these, making the other one theoretically rarer. But it might be a very long time before that happens!

You can't really count on relative rarity measures until you've seen maybe a dozen or two dozen soups for each object -- by which time there will be huge piles of other objects that have only one soup each, which will in all probability be much rarer than these two p7s. But almost any of the single-soup objects might have a reasonable claim to be Just As Rare As Any Other CGoL Object Found In Soup... until more data trickles in.

EDIT: The soup MathAndCode mentioned can be found here (xs44_0rb8bp6gmiczc8abojc1z33).

[MathAndCode]

However, this object was formed in a soup but did not survive until the end and is therefore listed in Catagolue as appearing in zero soups, so, in a way, it has been found in a soup but is rarer than objects that have only appeared in soups once. There are probably other rare objects for which the same thing has occurred, but most aren't lucky enough to be converted to a similar rare object instead of completely destroyed.

Speaking of that object, I managed to decrease its glider cost by one by constructing the blinker and R-sequence with four gliders instead of five.

Code: Select all

x = 51, y = 94, rule = B3/S23
48bo$48bobo$48b2o39$7bobo$o6b2o$o7bo$o2$5bo$4bobo$3bo2bo19bo$4b2o6bo11b
2o$12b2o3b2o6b2o$11bobo3bobo$17bo2$21b2o$20b2o$22bo35$32b2o$31b2o$33bo!

The loaf and blinker can be constructed together with three gliders.

Code: Select all

x = 11, y = 7, rule = B3/S23
4bo$4bobo$4b2o2$2bo5bobo$obo5b2o$b2o6bo!

This likewise reduces the cost of the related 44-cell still life by one glider.

Code: Select all

x = 57, y = 93, rule = B3/S23
55bo$54bo$54b3o38$7bobo$o6b2o$o7bo$o2$5bo$4bobo$3bo2bo19bo$4b2o6bo11b
2o$12b2o3b2o6b2o$11bobo3bobo$17bo2$21b2o$20b2o$22bo35$32b2o$31b2o$33bo!

[ColorfulGalaxy]

what is the name of the constellation formed by this reaction?

Code: Select all

x = 7, y = 9, rule = B3/S23
b2o$o2bo$3bo$3o3$4b3o$4bobo$4bobo!

This also appeared in the ash of xp0_catagolue.
I once asked about the same thing here.
Sorry, I can't find "Octomino II" on the wiki.

[bubblegum]

Sometimes it's called a "W" (shh don't tell anyone wings exist).

[otismo]

What currently holds the record for being the RAREST CGoL Object ever found in a soup ?

How do you measure relative rarity? ETC.

Achim F. did some work on relative rarity http://ash.jct.onl - has this been continued ?

How many CGoL objects have been found in only one soup ?

@ MAC

Would this be twice as rare - or infinitely more rare ?

Code: Select all

x = 21, y = 23, rule = B3/S23
11b2ob2o$11b2obobob2o$16bobobo$11b5o4bo$11bo3bob3o$13bobobo$12b2obo$
10bo5bo$10b5obo$14b2o$10b2o$9bobo$9b2o$5b2o$4bob5o$4bo5bo$5bob2o$3bobo
bo$b3obo3bo$o4b5o$obobo$b2obobob2o$5b2ob2o!

Thank You for Responding !

I Appreciate Your Time !

Cheers !

[toroidalet]

There are currently 8899 xs20's with only one (C1) soup and a similar number of xs21's.

An extremely optimistic bound on the rarity of your still life would be the other one squared times some really small constant (probably requiring a few septillion-nonillion (10^24-10^30) soups). However, the predecessor doesn't work when there are 2 copies, so it would probably be much, much rarer than that, so it is most likely somewhere in the "probably will never appear" department. (remember that the massive still lives that have appeared already are ones with relatively simple predecessors, and this one might not be so lucky)

[dvgrn]

Achim F. did some work on relative rarity http://ash.jct.onl - has this been continued ?

How many CGoL objects have been found in only one soup ?

I am mysteriously unable to access "http://ash.jct.onl", though that has happened to me a lot with links that you've posted -- I'm still not entirely clear why that would be. But yes, the last several years of distributed searching with apgsearch/Catagolue could be said to be a continuation of Achim Flammenkamp's census work from 2004, and Andrzej Okrasinski's screensaver and Nathaniel Johnston's TOLLCASS.

There are almost a quarter million objects (236,112 as of this writing) in the current C1 census on Catagolue. Over 100,000 of those objects are represented in only one soup. This includes oscillators and a few mostly switch-engine-based puffers. A few of those 100,000 objects will also be represented in the G1 census, and/or in one or more of the other symmetries, but then there are lots more single-soup objects to be found in the censuses for those symmetries (and nowhere else).

If you want to explore these, just browse to a census page on Catagolue like

https://catagolue.hatsya.com/census/b3s23/G1

and replace the word "census" with "textcensus" in the URL. I'm not giving the link here directly because the resulting pages can easily run into several megabytes -- they can take a while to load, and I think would maybe use up Catagolue's daily quota unnecessarily fast if a lot of people went to look at them. I've attached today's C1 text census in ZIP format.

Catagolue_C1_census_20Feb2021.zip

(1.56 MiB) Downloaded 101 times

[bubblegum]

I am mysteriously unable to access "http://ash.jct.onl", though that has happened to me a lot with links that you've posted -- I'm still not entirely clear why that would be.

I can access it fine, it's just a mirror of Achim Flammenkamp's census work (you linked to it right after, in fact).

Also, I just realised you double-space after full stops. Ah, phpBB.

[GUYTU6J]

...
Also, I just realised you double-space after full stops. Ah, phpBB.

Well, that happens on the LifeWiki too — see this revision. It loos more like a personal habit.

[bubblegum]

Well, that happens on the LifeWiki too — see this revision. It loos more like a personal habit.

I meant that dvgrn double-spaces after full stops, but phpBB reduces it to a single space.

[dvgrn]

Well, that happens on the LifeWiki too — see this revision. It loos more like a personal habit.

I meant that dvgrn double-spaces after full stops, but phpBB reduces it to a single space.

Yeah, I do (and the revision GUYTU6J pointed to is a good example of me doing it).

I've been trying to break the habit lately, but it was drilled into me as the Absolute Only Right Thing To Do After A Full Stop at an impressionable age, when I was learning to type ... on an electric typewriter, in the mid-1980s, when my family was pretty near the only household in town that owned a personal computer.

-- dv "Older Than The Internet" grn