Re: [ROOT] Lists

From: Valeri Fine (fine@bnl.gov)
Date: Fri Oct 19 2001 - 20:55:56 MEST


My guess he was speaking about "memory resident" objects.
But that's the guess.

Alberto, can you elaborate a little bit about your troubles ?
The first thing that comes in mind is just a regular 
"sort and binary search" approach.

                     Best regards, Valeri

-----
Dr.Valeri Fine
STAR/US Atlas                                    E-mail: fine@bnl.gov
Brookhaven National Lab                   Phone: +1 631 344 7806
Upton, NY 11973-5000                       FAX:     +1 631 344 4206
USA



----- Original Message ----- 
From: "Philippe Canal" <pcanal@fnal.gov>
To: "Alberto Pulvirenti" <alberto.pulvirenti@ct.infn.it>; <roottalk@pcroot.cern.ch>
Sent: Friday, October 19, 2001 2:48 PM
Subject: RE: [ROOT] Lists


> Hi Alberto,
> 
> Did you look into using a TTree.  TTree are specialized to handle
> a very large amount of objects and do selection on them.
> (See the many example in the tutorials and test directory, as well 
> as an extensive discussion in the User Guide).
> 
> Cheers,
> Philippe.
> 
> -----Original Message-----
> From: owner-roottalk@pcroot.cern.ch
> [mailto:owner-roottalk@pcroot.cern.ch]On Behalf Of Alberto Pulvirenti
> Sent: Friday, October 19, 2001 12:01 PM
> To: roottalk@pcroot.cern.ch
> Subject: [ROOT] Lists
> 
> 
> Hi to all rooters!
> If there is any who knows well the collection classes, he could give me 
> a clever suggestion.
> My problem is to collect many objects (~100000) and to visit the 
> collection to get the ones which, every time, satisfy some criteria that 
> I estabilished. But, when using the only one thing I know well, the 
> TObjArray, I didn't achieve the correct performance, and wasted many 
> time wisiting objects that I don't need.
> Maybe, it could be a good idea to use a THashList, but I'm not sure...
> 
> any suggestion?
> 
> Thanks by Alberto Pulvirenti
> 
> 



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