Hi Conrad,
You use a standard C++ array of doubles not a TArrayD.
In your code reading the Tree, do, eg:
double Etgenjet5[nmax]; //with nmax greater or equal to
the max value for nGenjet5.
T->SetBranchAddress("Etgenjet5",Etgenjet5);
On 6 Sep 2002, Conrad Steenberg wrote:
> Hi
>
> >From reading the user's manual I'm unsure how to read a variable array
> of doubles from a TTree. E.g.
>
> The TTree has a branch
>
*............................................................................*
> *Br 12 :nGenjet5 : nGenjet5/I
*
> *Entries : 638 : Total Size= 14992 bytes File Size =
0 *
> *Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00
*
>
*............................................................................*
>
> and another
>
>
*............................................................................*
> *Br 21 :Etgenjet5 : Etgenjet5[nGenjet5]/D
*
> *Entries : 638 : Total Size= 36769 bytes File Size =
0 *
> *Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00
*
>
*............................................................................*
>
>
> So in my Root file I do
>
> Int_t i, j, nGenjet5;
> TArrayD *Etgenjet5=0Etgenjet5;
>
> //[ Set up the TTree from a file here] then
>
> Int_t nevent = (Int_t) T->GetEntries();
> T->SetBranchAddress("nGenjet5",&nGenjet5);
> T->SetBranchAddress("Etgenjet5",&Etgenjet5);
>
> for (i=0;i<nevent;i++) // Loop over Events
> {
> T->GetEntry(i);
> for (j=0;j<nGenjet5;j++)
> printf("j=%d value=%f\n",j,Etgenjet5[j]);
>
> }
>
> This quicjly causes a segfault...
>
> Any ideas would be appreciated :-)
>
> Conrad
On 6 Sep 2002, Conrad Steenberg wrote:
> Hi
>
> >From reading the user's manual I'm unsure how to read a variable array
> of doubles from a TTree. E.g.
>
> The TTree has a branch
> *............................................................................*
> *Br 12 :nGenjet5 : nGenjet5/I *
> *Entries : 638 : Total Size= 14992 bytes File Size = 0 *
> *Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
> *............................................................................*
>
> and another
>
> *............................................................................*
> *Br 21 :Etgenjet5 : Etgenjet5[nGenjet5]/D *
> *Entries : 638 : Total Size= 36769 bytes File Size = 0 *
> *Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
> *............................................................................*
>
>
> So in my Root file I do
>
> Int_t i, j, nGenjet5;
> TArrayD *Etgenjet5=0;
>
> //[ Set up the TTree from a file here] then
>
> Int_t nevent = (Int_t) T->GetEntries();
> T->SetBranchAddress("nGenjet5",&nGenjet5);
> T->SetBranchAddress("Etgenjet5",&Etgenjet5);
>
> for (i=0;i<nevent;i++) // Loop over Events
> {
> T->GetEntry(i);
> for (j=0;j<nGenjet5;j++)
> printf("j=%d value=%f\n",j,Etgenjet5[j]);
>
> }
>
> This quicjly causes a segfault...
>
> Any ideas would be appreciated :-)
>
> Conrad
>
> --
> *-----------------------------------------*
> | Conrad Steenberg |
> | Caltech, Mail Code 356-48 |
> | Pasadena, CA, 91125 |
> | e-mail: conrad@hep.caltech.edu |
> | Tel: (626) 395-8758 |
> *-----------------------------------------*
>
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