[squeak-dev] Interesting survey about smalltalk

Jimmie Houchin jdev at cyberhaus.us
Mon Jun 21 04:52:02 UTC 2010


On 6/20/2010 10:41 AM, Lawson English wrote:
> On 6/20/10 6:08 AM, Nicolas Cellier wrote:
>> 2010/6/20 Michael Haupt<mhaupt at gmail.com>:
>>> Hi Nicolas,
>>>
>>> On Sun, Jun 20, 2010 at 11:17 AM, Nicolas Cellier
>>> <nicolas.cellier.aka.nice at gmail.com>  wrote:
>>>> About 8) :  True, every single operation results in memory allocation
>>>> / garbage collection, a burden for number crunching.
>>> really?
>>>
>>> There is this nice book by Didier Besset called "Object-Oriented
>>> Implementation of Numerical Methods. An Introduction with Java and
>>> Smalltalk.: An Introduction with Java and Smalltalk". It can't be
>>> *that* bad. :-)
>> Agree, "not worse than Matlab" was the meaning of my message.
>>>> My own answer was: use C/FORTRAN for optimized number crunching
>>>> functions. Use Smalltalk for any higher level/GUI function (via
>>>> DLLCC/FFI). We may have more than 1 hammer in your toolset!
>>> With GPU connectivity things emerging, number crunching might even be
>>> an interesting area for Smalltalk.
>>>
>>> Best,
>>> Michael
>> Yes, this falls in vectorizing the operations.
>> But I would go for a GPU-BLAS implementation available to any language
>> (Smalltalk and C as well).
>>
>> Nicolas
> How many parallel squeak processes would be required to = the speed of 
> one native library for arbitrary precision math, or for other math 
> intensive purposes?
>
> Lawson

Hello,

I would love to be using Squeak for my financial application. Numerical 
performance isn't currently what is stopping me. My problem is that I 
require interfacing with a Windows COM dll and in a future version with 
a Java library. Hopefully at some point I will be able to port to 
Squeak. I would much prefer it to using Python, which is what I am 
currently using.

I didn't even know Squeak was in the running until I discovered the 
Matrix class. And for what I need to do it performs reasonably 
adequately. However Squeak does not to my knowledge have a comprehensive 
collection of mathematics methods to be able to be applied to a variety 
of data. Currently I am using Python and Numpy which has a nicely 
optimized Mathematics/Scientific set of functions using optimized 
C/Fortran libraries. I would love to see Squeak compete in this area. In 
fact the Numpy people are currently refactoring the library to turn it 
into a C library usable by other languages.

Here is some samples from my experimentation.

Some of what I am doing is doing rolling calculations over my dataset.

dataset is one weeks worth of OHLC data of a currency pair.

In Squeak I have.

ttr := [
   1 to: ((m rowCount) -500) do: [:i || row rowSum rowMax rowMin 
rowMedian rowAverage |
   row := (m atRows: i to: (499+i) columns: 5 to: 5).
   rowSum := row sum.
   rowMax := row max.
   rowMin := row min.
   rowMedian := row median.
   rowAverage := row average.
   omd add: {rowSum . rowMax . rowMin . rowMedian . rowAverage}]] timeToRun.

Squeak:  17 seconds,  with Cog 4.2 seconds  (nice work guys 
(Eliot/Teleplace)

In Python/Numpy I have.

import numpy as np
def speedtest(array,omd):
     t1 = time.time()
     for i in range(0, (len(a)-500)):
         rowmax = np.max(a['bidclose'][i:i+500])
         rowmin = np.min(a['bidclose'][i:i+500])
         rowsum = np.sum(a['bidclose'][i:i+500])
         rowmedian = np.median(a['bidclose'][i:i+500])
         rowmean = np.mean(a['bidclose'][i:i+500])
         omd.append((rowsum, rowmax, rowmin, rowmedian, rowmean))
     return time.time()-t1

Python:  .7 seconds

Python/Numpy performs well, is reasonably nice to work with. But I would 
give up the performance to be able to use Squeak. The live environment 
and debugging would be invaluable for experimentation.

Hopefully this will give you some idea.

Jimmie



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