Re: Sorting a TOrdCollection

From: Fons Rademakers (Fons.Rademakers@cern.ch)
Date: Thu May 22 1997 - 13:25:34 MEST


Hi Jim,

   this is an obvious area for profiling. Currently we use a quicksort
algorithm in TSeqCollection::QSort(). This calls the objects Compare()
function. On all levels we get some overhead and I want to see where
we loose most. I'll investigate and will let you know.

Cheers, Fons.


James M White wrote:
> 
> Greetings,
>         I have a TOrdCollection of TObjStrings that I want to sort.  I
> used the Sort() method in the TOrdCollection class but it seems VERY
> slow.  It took about 400 CPU second on a Dec Alpha to sort a
> TOrdCollection containing 22,000 TObjStrings.  This seems to take
> longer than it should and I eventually will need to sort a
> TOrdCollection with over 1,000,000 TObjStrings.  Am I doing something
> wrong?  Is there a way to speed it up?
>                                 Jim
> 
> --
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> Jim White                                     505-667-0398
> Los Alamos National Laboratory          (FAX) 505-665-5220
> MS B-265
> Los Alamos, NM 87545
> jmw@lanl.gov        http://www.c3.lanl.gov/~jmw/info.shtml
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

-- 
Org:    CERN, European Laboratory for Particle Physics.
Mail:   1211 Geneve 23, Switzerland          Phone: +41 22 7679248
E-Mail: Fons.Rademakers@cern.ch              Fax:   +41 22 7677910



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