I've been working on a program over the last few days to evolve
cellular automata rules using a genetic algorithm. Luckily, this email
has nothing to do with CAs but everything to do with Haskell
performance.
For those who don't know, a CA is represented as a row of cells, where
each can be
One observation is that you're doing a lot of redundant Bool - Int
conversion.
As you iterate across the array in fillArray, the rule you are using for the
next cell is almost entirely determined by the rule you are using for the
current cell; lop off the top bit, shift left by one, and add the
On 11/13/07, Ryan Ingram [EMAIL PROTECTED] wrote:
Also, what stops getRule from going off the end of the array? I didn't
see anything that prevented that in the code, and you're using unsafeAt,
which seems like a potential bug.
Never mind, I realized this is a ring buffer with `mod` s.
On Nov 13, 2007 2:21 PM, Ryan Ingram [EMAIL PROTECTED] wrote:
Never mind, I realized this is a ring buffer with `mod` s. That's another
slow operation when you're doing code as tight as this. If you can
guarantee the ring is a power of 2 in size you can use a mask instead, or
use my
On Tue, Nov 13, 2007 at 02:45:33PM -0800, Justin Bailey wrote:
On Nov 13, 2007 2:21 PM, Ryan Ingram [EMAIL PROTECTED] wrote:
Never mind, I realized this is a ring buffer with `mod` s. That's another
slow operation when you're doing code as tight as this. If you can
guarantee the ring is
Sure, if the ring size is a power of two, and a is greater than or equal
to 0, then
a `mod` ringSize == a .. (ringSize - 1)
that is:
a `mod` 8 == a .. 7
a `mod` 256 == a .. 255
etc.
On 11/13/07, Justin Bailey [EMAIL PROTECTED] wrote:
On Nov 13, 2007 2:21 PM, Ryan Ingram [EMAIL PROTECTED]
On Nov 13, 2007 2:49 PM, Stefan O'Rear [EMAIL PROTECTED] wrote:
About how wide are your rules usually?
7 bits (3 neighbors on each side plus the current cell).
Justin
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I implement bit shifting to get the next rule, as you suggested, and
that cut my run time by 75%. It went from 200 seconds to do 100 rules
on 100 CAs to 50 seconds. Amazing.
Justin
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On Tue, 2007-11-13 at 14:21 -0800, Ryan Ingram wrote:
On 11/13/07, Ryan Ingram [EMAIL PROTECTED] wrote:
Also, what stops getRule from going off the end of the array?
I didn't see anything that prevented that in the code, and
you're using unsafeAt, which seems like a
On Friday 16 March 2007 21:24, Ian Lynagh wrote:
On Sun, Mar 11, 2007 at 08:18:44PM +, Dominic Steinitz wrote:
I have re-written the sha1 code so that it is (hopefully) easy to see
that it faithfully implements the algorithm (see
http://www.itl.nist.gov/fipspubs/fip180-1.htm). Having
On Sat, Mar 24, 2007 at 01:46:33PM +, Dominic Steinitz wrote:
Thanks. I'm trying to build just SHA1 but I am getting the following linker
errors. Do you know what option I should be adding?
[EMAIL PROTECTED]:~/sha11 ghc -o perfTest
perfTest.hs -iIgloo/darcs-unstable/src --make -lz
On Friday 16 March 2007 21:29, David Brown wrote:
Ian Lynagh wrote:
On Sun, Mar 11, 2007 at 08:18:44PM +, Dominic Steinitz wrote:
I have re-written the sha1 code so that it is (hopefully) easy to see
that it
faithfully implements the algorithm (see
On Sun, Mar 11, 2007 at 08:18:44PM +, Dominic Steinitz wrote:
I have re-written the sha1 code so that it is (hopefully) easy to see that it
faithfully implements the algorithm (see
http://www.itl.nist.gov/fipspubs/fip180-1.htm). Having got rid of the space
leak, I have been trying to
Ian Lynagh wrote:
On Sun, Mar 11, 2007 at 08:18:44PM +, Dominic Steinitz wrote:
I have re-written the sha1 code so that it is (hopefully) easy to see
that it
faithfully implements the algorithm (see
http://www.itl.nist.gov/fipspubs/fip180-1.htm). Having got rid of the
space
leak, I have
Hi
I notice that there's not much user-accessible documentation of what you
can expect GHC (or some other Haskell implementation) to do and not do
with a given piece of code.
Yhc/nhc/Hugs - nothing
GHC - inlining, simplification, fusion if you use the build in
functions in a specified way,
I have re-written the sha1 code so that it is (hopefully) easy to see that it
faithfully implements the algorithm (see
http://www.itl.nist.gov/fipspubs/fip180-1.htm). Having got rid of the space
leak, I have been trying to improve performance.
Currently, the haskell code is 2 orders of
On Sun, Mar 11, 2007 at 08:18:44PM +, Dominic Steinitz wrote:
Word128 ai bi ci di ei = ss
128 is not divisible by 5. You should probably rename that type :)
Stefan
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On Sunday 11 March 2007 20:46, Stefan O'Rear wrote:
On Sun, Mar 11, 2007 at 08:18:44PM +, Dominic Steinitz wrote:
Word128 ai bi ci di ei = ss
128 is not divisible by 5. You should probably rename that type :)
Stefan
I must have been thinking of MD5. Yes Word160 would be better.
Dominic Steinitz wrote:
Any help would be appreciated.
I notice that there's not much user-accessible documentation of what you
can expect GHC (or some other Haskell implementation) to do and not do
with a given piece of code. For example, you have a lot of little
definitions that clearly
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