Browse MyClass in TTree

ROOT
1

Dear ROOTers,
I’ve searched a lot for a solution, but I’ve found nothing!
I’ve created some classes which inherit from TObject:

[code]class MyTrack : public TObject {
…
vector coordinate;
…
};

class MyDetector : public TObject {
…
vector tracks;
…
};

class MyEvent : public TObject {
…
vector info;
vector detectors;
…
};[/code]

All classes do perfectly work inside ROOT.

My problem is that when I store a MyEvent class in a TTree, I can’t use the Draw method to Draw all the coordinates:

returns:

Warning in <TTreeFormula::DefinedVariable>: TTreeFormula support only 2 level of variables size collections. Assuming '@' notation for the collection coordinate. Error in <TTreeFormula::DefinedVariable>: coordinate is not a datamember of vector<MyTrack> Error in <TTreeFormula::Compile>: Bad numerical expression : "MyEvent.detectors.tracks.coordinate"

I don’t want ROOT to assume “’@’ notation for the collection coordinate”!

How can I create a TTree without loseing the Draw functionality?
Is it the only chance to create an entry for each coordinate?

Thanks a lot to everyone!
Nicola

2

Hi,

The only options to make this work in TTree::Draw is to fix some of the dimensions.
For example you can do:mytree->Draw("MyEvent.detectors[0].tracks.coordinate"); mytree->Draw("MyEvent.detectors[1].tracks.coordinate>>+htmp");

Probably better yet, if the number of dectectors is fixed, you might simply want to replace the vector by a fixed size array.

Cheers,
Philippe.

3

Hello,
Thanks for the answer.

I’ve tryed to fix some of the indexes, but it returns the same error!
I’ve tryed also with an array in place of a vector, but it has the same behavior.

cheers,
Nicola

4

Hi,

The last thing to try is:mytree->Draw("MyEvent.detectors.tracks.coordinate@.at(0)"); mytree->Draw("MyEvent.detectors.tracks.coordinate@.at(1)>>+htmp");

Cheers,
Philippe.

PS. Did you try with a fixed size array?