Hi this is just a message regarding Jason's question
Couldn't you write the histograms into a TTree? that would solve the
problem of comparing it to other TTrees with histograms. Then you have the
problem of random access, so you decide.
One problem I see with Rene's method is that if you have something else in
your directory you would write that too. That's not big deal though.
does this make sense?
Javier
> Date: Wed, 14 May 2003 21:25:30 +0200 (MEST)
> From: Rene Brun <Rene.Brun@cern.ch>
> Subject: Re: [ROOT] Writing array of histograms
>
> Hi Jason,
>
> This is quite easy to do. Let me assume that you have created several
> histograms TH1 *h1,*h2,*h3, etc in the current directory.
> You can get a pointer to the list in memory with
> TList *list = gDirectory->GetList();
>
> then write this list as one single key in a Root file with:
> TFile f("junk.root","new");
> list->Write("allhists",TObject::kSingleKey);
>
> To read the list again in memory, you can do
> TFile f("junk.root");
> TList *list = (TList*)f.Get("allhists");
> list->ls();
>
> Rene Brun
This archive was generated by hypermail 2b29 : Thu Jan 01 2004 - 17:50:11 MET