Re: CopyTree'ing large TTrees

Hi Ilya,

Did you do something like:

    TFile *output = new TFile("shortfile.root","RECREATE");     TTree* tmp = CALIWAVE->CopyTree("FT==0 && slot==2 && channel==1");     tmp->Write();

to insure that the output TTree is properly attached to the output files?

Cheers,
Philippe.

Ilya Orlov wrote:
> Hello roottalk,
>
> I'm trying to select the records from the TTree having a specific
> values of several leaves.
> I have TTree* CALIWAVE being of enormous size (smth like 40 millions
> of records), but I need only ~1000 of them to be selected.
>
> When I say
> CALIWAVE->Scan("Amplitude","FT==0 && slot==2 && channel==1");
> I get the array of 768 records printed out, and everything is fine and quick.
>
> But when I say
> TTree* tmp = CALIWAVE->CopyTree("FT==0 && slot==2 && channel==1");
> to get the access to the leaves of the selected records from my
> script, I get the bad_alloc exception.
> That happens both in CINT and in my C program using ROOT libraries.
>
> Why is it so and how can I manage to do what I want? :)
>
> Thank you in advance.
>
> --
> Best regards,
> Ilya Orlov.
>
>
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Received on Sat Sep 12 2009 - 17:33:35 CEST