Re: deleting hist from memory

From: Axel Naumann <axel_at_fnal.gov>
Date: Thu, 17 Mar 2005 15:14:40 -0600

Sorry Boris,
what I sent only works for files. Use TDirectory::GetList() for in-memory objects:

>> TIter nextobj(gROOT->GetList());
>> TObject *obj=0;
>> while ((obj = nextobj()))
>> if (obj->Class()
>> && obj->Class()->InheritsFrom( TH1::Class() )
>> delete obj;

Axel.

Axel Naumann wrote:

> Hi Boris,
> use "delete obj". gDirectory could also be the current file, so
> explicitly using gROOT is safer. And this code snippet should be a bit
> faster:
> 
> 

>> TIter nextkey(gROOT->GetListOfKeys());
>> TKey *key;
>> while (key = (TKey*)nextkey())
>> if (key->Class()
>> && key->Class()->InheritsFrom( TH1::Class() )
>> delete key->ReadObj();

> 
> 
> Note how it compares pointers instead of strings, only tests for TH1
> (TH2 derives from TH1, so whatever is satisfied by
> InheritsFrom(TH2::Class()) will also be satisfied by
> InheritsFrom(TH1::Class())), and reads the key only if the class matches
> (which is not really relevant for in memory objects).
> 
> Axel.
> 
> Boris Skorodumov wrote:
> 

>>dear rooters,
>>
>>i have simple question:
>>
>>suppose i created in memory several 1d and 2d histogram. {via TH1D *h =
>>new TH1D("h",..... ) ....}
>>after that im filling them with some criteria.
>>Finally i am deleting them from memory. Now i whould like to
>>run script again to do the same procedure. Just to be save, i am trying
>>in script delete all of the histograms in memory via next script:
>>
>> TIter nextkey(gDirectory->GetListOfKeys());
>> TKey *key;
>>
>> while (key = (TKey*)nextkey()) {
>>
>> TObject *obj = key->ReadObj();
>> if ( obj->IsA()->InheritsFrom( "TH2" ) ||
>>obj->IsA()->InheritsFrom( "TH1" ))
>> obj->Delete();
>> }
>>
>>but still i see all OBJ in memory. is it something wrong ?
>>
>>
>>thank you,
>>
>>boris.
>>

>
> Received on Thu Mar 17 2005 - 22:14:45 MET