| Re: looking for sort procedure [message #7755 is a reply to message #7750] |
Thu, 16 January 1997 00:00   |
Pirmin Kaufmann
Messages: 3
Registered: January 1997
|
Junior Member |
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William Thompson wrote:
>
> kak@sat.ipp-garching.mpg.de (Karl Krieger) writes:
>
>> "R. Bauer" <r.bauer@kfa-juelich.de> writes:
>
>>> It was surprising me that's idl's build-in sort procedure is very very
>>> slow.
>
>>> for this example it needs on may RS6000 AIX more than 2 minutes.
>
>>> a = indgen(10000)
>>> b = [a,a]
>>> print,systime(0)
>>> s = b(sort(b))
>>> print,systime(0)
>
>>> end
>
>>> This is much too long.
>
>> Hi all,
>
>> there seems to be a bug in the implementation of this routine:
>> I tested it on a SUN Ultrasparc and on an IBM RS6000, which
>> has about the same speed (at least for the Monte Carlo simulation
>> coded in F77, which usually runs on these boxes).
>
>> Result for SUN: below 1 second, 6 seconds for a=lindgen(100000L)
>> Result for IBM: about 145 seconds
>
>> Is this a known bug/feature? There seems to be a major problem
>> either in the implementation of sort or in the way it uses
>> the machine's resources (bad optimization?).
>
> I also tried the above example on a DEC AXP 3000/600 where it took about 60
> seconds. I wonder if there's something in the code that is optimized for Sun
> workstations, maybe going back to the days when the first Unix port of IDL was
> called SunIDL?
Probably not. It only takes a few seconds on other non-unix, non-sun
(but, more important, non-ibm) machines.
Macintosh IIfx (40 MHz, 68030 CPU, 68882 co-processor): 5 seconds
VAXstation 4000-90A: less than 1 second
--
------------------------------------------------
Pirmin Kaufmann pkaufmann@etl.noaa.gov
NOAA/ERL/ETL phone: 303 497-6613
325 Broadway R/E/ET7 fax: 303 497-6978
Boulder, CO 80303-3328
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