Rene Brun
On Thu, 25 Mar 1999, Leszek Kidon wrote:
> Hi
> We have problems to draw 2 dimensional correlations using TTree with
> branches based on TClonesArray.
> We have 2 branches with 2 arrays . One has 3 elements another 2 elements
> (For example one branch could be a detector with 3 hits and another a
> detector with 2 hits).We would like to draw 2 dimensional
> correlation between hits on these 2 detectors (for example positions
> measured on both detectors).
> We have expected ROOT to draw all possible combinations of these hits
> (6=3x2). We get different results depending on order we put in Draw
> command these 2 elements of branches.
> How one can get these 2-dimensional correlations without writing a
> dedicated macros?
>
> Best regards
> Leszek
>
> We inlcude a simple macro with the definition of this TTree.
>
> {
> TFile *f = new TFile("test.root", "RECREATE");
>
> TClonesArray *atab = new TClonesArray("AAA", 16);
> TClonesArray *btab = new TClonesArray("BBB", 16);
>
> TTree *tree = new TTree("T", "test");
>
> tree->Branch("AAA", &atab, 64000, 1);
> tree->Branch("BBB", &btab, 64000, 1);
>
> new((*atab)[0]) AAA(5, 6);
> new((*atab)[1]) AAA(4, 5);
> new((*atab)[2]) AAA(3, 4);
>
>
> new((*btab)[0]) BBB(7, 4);
> new((*btab)[1]) BBB(6, 3);
>
>
> tree->Fill();
>
> f->Write();
> f->Close();
>
> delete f;
> }
>
> Class definition:
>
>
> #include <TObject.h>
> #include <TClonesArray.h>
>
> class AAA : public TObject
> {
> public:
> AAA(){A1 = 0; A2 = 0;}
> AAA(int a1, int a2){A1 = a1; A2 = a2;}
>
> int A1;
> int A2;
>
> ClassDef(AAA, 1)
> };
>
> class BBB : public TObject {
> public:
> BBB(){B1 = 0; B2 = 0;}
> BBB(int b1, int b2){B1 = b1; B2 = b2;}
>
> int B1;
> int B2;
>
> ClassDef(BBB, 1)
> };
>
>