What is CA for?
fasisi
I just studied CA. And I have read that CA can be used to build
intelligent, or a CA can be universal (that is can compute anything).
Can you explain how to make use some CA? If CA is more than a way to
make pattern, how to utilizes a CA?
Thank you
jeanh
Hello Fasisi,
CA can be used for quite a lot of things indeed...
I am using them for environmental modeling. It is used for land-use
change simulations, where the content of the cells surrounding a central
cell defines how this cell is going to evolve (for example, a cell that
is "agriculture" but has 3 urban neighbors will likely become urban,
while if it is surrounded by forest or other agriculture cells, it will
remain agriculture.)
CA are also used for fire propagation modeling, seismic activities,
prey-predator (wildlife) relationships etc.
I have heard CA can be used in computer sciences for encoding, random
number generators etc.
Jean
fasisi
Hello,
Jean, thank you for replying.
Do you know that a CA can be said universal? It is said that a
universal CA can compute anything. How to make use a CA as computation
tool?
I am missing the point as to how to make use a CA. Can you help me?
Maybe you can point me some examples with explanation?
Thank you
Sjouke Burry
computer, however I dont think that besides small demos
anybody has managed to do so.
But as a means to describe operations on datasets, like cellular
automata 2D or higer, works sort of.
You might buy a few books, like
ISBN 0-262-20069-0 Cellular automata machines Margolus and Toffoli
ISBN 0-444-86850 X Cellular automata workshop
ISBN 0-670-81178-5 Chaos James Gleick
ISBN 0-7167-1588-0 Wheels,life and...... Gardner
ISBN 3-87664-101-2 or
ISBN 0-89573-223-8 (VHCPublishers) Deterministic Chaos ,Schuster
The first one might be the best one, the second gives publications
from about 20 scientists.
But that is far from an implemented universal computer.
calcyman
I have built a Life pattern to compute the digits of phi. Studying
this pattern may help answer your question:
Kent Paul Dolan
> fasisi <frans.indroy...@gmail.com> wrote:
>> I just studied CA. And I have read that CA can be
>> used to build intelligent, or a CA can be
>> universal (that is can compute anything).
>> Can you explain how to make use some CA? If CA is
>> more than a way to make pattern, how to utilizes
>> a CA?
> I have built a Life pattern to compute the digits
> of phi. Studying this pattern may help answer your
> question:
> http://calcyman.awardspace.co.uk/life-massive/phi.mc
Okay, generating the results in decimal digits is a
bit of a tour-de-farce, but at least it's easy to
read. You might have wanted to warn the casual
onlooker to speed Golly 2.0 up to at least 8^6 (8^8
works even better) to see anything happen in a human
lifetime. I was still at just the two digits 1.6
after 6*10^9 Golly generations.
Sending the results _through_ the previous results
to build up a digit on the far side (if what seems
to be happening is what is happening), so that the
prior digits don't need to be moved is also a bit
cute.
Well done, altogether. I have your patience, but not
in your field.
xanthian.
Kent Paul Dolan
> fasisi <frans.indroy...@gmail.com> wrote:
>> I just studied CA. And I have read that CA can be
>> used to build intelligent, or a CA can be
>> universal (that is can compute anything).
>> Can you explain how to make use some CA? If CA is
>> more than a way to make pattern, how to utilizes
>> a CA?
> I have built a Life pattern to compute the digits
> of phi. Studying this pattern may help answer your
> question:
> http://calcyman.awardspace.co.uk/life-massive/phi.mc
Okay, generating the results in decimal digits is a
bit of a tour-de-farce, but at least it's easy to
read. You might have wanted to warn the casual
onlooker to speed Golly 2.0 up to at least 8^6 (8^8
works even better) to see anything happen in a human
lifetime. I was still at just the two digits 1.6
after 6*10^9 Golly generations.
Sending the results _through_ the previous results
to build up a digit on the far side (if what seems
to be happening is what is happening), so that the
prior digits don't need to be moved is also a bit
cute.
Well done, altogether. I have your patience, but not
in your field. How long did that take to construct,
and how large were hte prebuilt kit parts from which
you built it?
xanthian.
calcyman
> onlooker to speed Golly 2.0 up to at least 8^6 (8^8
> works even better) to see anything happen in a human
> lifetime. I was still at just the two digits 1.6
> after 6*10^9 Golly generations.
Step size 8^9 is optimal for computers with approximately 1 gigabyte
of memory. In one hour, it is possible to see the first 30 digits,
which takes about 10^12 generations.
The state of the pattern after 1.25 * 10^12 generations is here:
http://calcyman.awardspace.co.uk/life-massive/phi+1250G.mc
The "1.6" is actually hard-coded into the program; all of the other
digits are calculated as sqrt(1.25), where the digits are extracted
using the standard pencil-and-paper square root algorithm. The
internal arithmetic is actually performed in binary, even though it
outputs in decimal. Surprisingly, this doesn't require any base-
conversion, so the pattern produces digits in O(n^3) time.
> Sending the results _through_ the previous results
> to build up a digit on the far side (if what seems
> to be happening is what is happening),
Yes, the digits are sparse enough that the gliders from the printer
can pass through them without touching the blocks.
> Well done, altogether. I have your patience, but not
> in your field. How long did that take to construct,
> and how large were hte prebuilt kit parts from which
> you built it?
The largest pre-built component was the articulated arm, courtesy of
Paul Chapman and Dave Greene, at about 600 * 600 pixels. I developed
all of the computational circuitry myself, such as the binary and
unary registers, the addition, subtraction and decimal shift units,
and (of course) the microprogram.