Re: [BLAST_ANAWARE] question about storing non-class values in a root file

From: Taylan Akdogan (akdogan@MIT.EDU)
Date: Tue Sep 21 2004 - 17:59:48 EDT

Hi Aaron,

I can tell why it does not work (and a possible work-around.)

Float_t is a typedef (for float), not an object. So, "charge->" is
illegal because it is simply "(float)->"

The only work around I know (it is ugly!) is like this:

class Test : public TObject {public:double charge;};
Test t;
t.charge = 1.3;
t.Write();

Maybe, you can consider to include everything (TH1F, Float_t...)
related to a "quantity" into an object, and write that single object
into TFile.

Taylan 

--
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Taylan Akdogan              Massachusetts Institute of Technology
akdogan@mit.edu                             Department of Physics
Phn:+1-617-258-0801                Laboratory for Nuclear Science
Fax:+1-617-258-5440                                  Room 26-402b
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On Sep 21, 2004, at 5:28 PM, Aaron Joseph Maschinot wrote:

>
> in addition to storing a histogram in a root file, i would like to also
> store the charge for the histogram also in the root file.  the charge
> would simply be a Float_t or Double_t.  however, since neither or these
> are explicitly root classes, they do not have a Write() function and 
> thus
> can't be written to file per norm:
>
> {
>   TH1F *hist;
>   Float_t charge;
>
>   f=new TFile("crap.root","recreate");
>
>   hist->Write();   //good!
>   charge->Write(); //hogwash! (that's the kentucky in me coming out 
> :^) )
>
>   f->Close();
> }
>
> does anyone know how to write Float_t's, Int_t's, etc. to root files?  
> i'm
> sure it's a simple answer that i'm just not thinking about...
>
> aaron

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