Re: array dimension

From: Rene BRUN <rene.brun_at_cern.ch>
Date: Fri, 04 Feb 2005 09:07:57 +0100

Hi Claus,

Because a branch may have more than one leaf, you must access the leaf. For instance using $ROOTSYS/test/Event.h with

    Int_t          fNvertex;
    UInt_t         fFlag;
    Double32_t     fTemperature;
    Int_t          fMeasures[10];
    Double32_t     fMatrix[4][4];

    Double32_t *fClosestDistance; //[fNvertex]

showing fix size arrays and variable length array (fClosestDistance), you can get the current size of the corresponding leaf with

   T->GetEntry90);
   T->GetLeaf("fMeasures")->GetNdata();
   T->GetLeaf("fClosestDistance")->GetNdata()
   T->GetLeaf("fMatrix")->GetLen()

Rene Brun

Claus Horn wrote:
> Dear ROOTers,
>
> I have the following question:
>
> Given a pointer to a TBranch,
> to a branch which holds an array
> (e.g. of float)
> how can I get to know the dimension
> of this array ?
>
> cherrs,
>
> Claus
>
Received on Fri Feb 04 2005 - 09:08:02 MET