Re: Hardware to run Octave

Às 06:38 de 20/02/21, Etienne Grossmann escreveu:
>
>   Hi Ramon,
>
> sorry, I don't have much advice to offer on a new device, I use old 
> hardware too, but don't have bulky tasks for Octave.
>
>   About the parallel package. I never had luck either until today when 
> I saw actual examples here: http://wiki.octave.org/Parallel_package. 
> Did you try these examples? They kind of work for me (w/ Octave 6.1):
>
>     *>> function y = my_func(x), y = 42 * x; end **# Try with
>     command-line-defined function*
>     *>> pararrayfun (4, @my_func, 1:8)*
>     *>> my_func(3)*
>     ans = 126
>     *>> pararrayfun (4, @(x) my_func(x), 1:8) # Why no output?*
>
>     *                                        # Try with file-defined
>     function*
>
>     *>> system('echo "function y = my_func2(x), y = 42 * x; end" >
>     my_func2.m')*
>     ans = 0
>     *>> addpath('.')*
>     *>> pararrayfun (4, @(x) my_func2(x), 1:8)* *# Still no output?*
>     *>> my_func2(4)*
>     ans = 168
>     *>> arrayfun (@(x) my_func2(x), 1:8)* *# This works but is not
>     parallel*
>     ans =
>
>         42    84   126   168   210 252   294   336
>
>     *>> pararrayfun (4, @(x) my_func2(x), 1:8)*
>     *>> z = pararrayfun (4, @(x) my_func2(x), 1:8)* *# Aha!A return
>     value is needed?*
>     z =
>
>         42    84   126   168   210 252   294   336
>
>     *>> z = pararrayfun (4, @(x) my_func(x), 1:8) # That's not the end
>     of the story*
>     z =
>
>       -1  -1  -1  -1  -1  -1  -1  -1
>     *>> z = pararrayfun (4, @my_func, 1:8) # CL-defined my_func() is
>     jinxed?*
>     z =
>
>       -1  -1  -1  -1  -1  -1  -1  -1
>
>     *>> z = pararrayfun (4, @my_func2, 1:8) # But file-defined
>     my_func2() seems OK*
>     z =
>
>         42    84   126   168   210 252   294   336
>
>     *# Let's check parallelism... LGTM*
>
>     *>> system('echo ''function y = my_delay_func(x), y = 42 * x;
>     printf("Starting %i\\n", x); pause(2); printf ("--Ending %i\\n",
>     x); end'' > my_delay_func.m')
>     *ans = 0
>     *>> system ('cat my_delay_func.m')
>     *function y = my_delay_func(x), y = 42 * x; printf("Starting
>     %i\n", x); pause(2); printf ("--Ending %i\n", x); end
>     ans = 0
>     *>> my_delay_func(3)
>     *Starting 3
>     --Ending 3
>     ans = 126
>     *>> z = pararrayfun (4, @my_delay_func, 1:8)
>     *Starting 1
>     Starting 4
>     Starting 3
>     Starting 2
>     --Ending 1
>     Starting 5
>     --Ending 4
>     Starting 6
>     --Ending 3
>     --Ending 2
>     Starting 7
>     Starting 8
>     --Ending 5
>     --Ending 6
>     --Ending 7
>     --Ending 8
>     z =
>
>         42    84   126   168   210   252   294   336
>
>
>    Does this not work for you? If not, what output do you get w/ the 
> above command? What version of Octave are you using?
>
>     HTH,
>
>     Etienne
>
>
>
> On Thu, Feb 18, 2021 at 7:47 AM Jose Ramom Flores das Seixas 
> <[email protected] 
> <mailto:[email protected]>> wrote:
>
>     Hi
>
>     As part of a research project, I wrote a program that takes about 17
>     hours to produce the result, using only one of the processor cores. I
>     tried to use the parallel package, but without success.
>
>     Since the amount of time it takes to see the results is so long, the
>     process of checking and correcting errors is very slow, not to
>     mention
>     that in my office the power goes out every now and then, wasting
>     hours
>     spent on calculations.
>
>     My current computer will soon be 10 years old, and I was thinking of
>     buying a new one. Its CPU is an Intel i52500K @ 3.30 GHz with 4 cores
>     and 4 threads.
>
>     One of the goals I have for the new PC is for it to run Octave
>     nicely.
>     Previously processors increased their power by, among other things,
>     increasing the processor speed. But for a number of years now, the
>     speed
>     of new processors has not increased, and other methods have been
>     used to
>     improve them, such as using more cores.
>
>     So I'd like to read your opinions on which hardware would be more
>     suitable for running octave.
>
>     Surely yours
>
>     Ramom
>
>
>
Thanks for the tips.

I was able to reproduce the examples, and even made new attempts 
successfully. But I have not yet been able to apply the *pararrayfun* 
command to my program, since the function to be parallelized is quite 
complex. I'm still trying it.

Surely yours
Ramom