Looping over several MakeClass objects

ROOT
1

Hi,

I think this is a very basic question, but I cannot seem to find the solution.

I have a root macro than simply does something like this:

void mylooper(){
string rootfiles;
rootfiles=*.root;

gROOT->LoadMacro("MyNTupleLooper.C++g");
MyNTupleLooper *a = new MyNTupleLooper();
a->AddFiles(rootfiles.c_str());
a->Loop();
}

Were MyNTupleLooper.C is a lopper class made by MakeClass and where I have modified MakeClass to handle a chain of files (The AddFiles function)

this works perfectly.

Now, I have wanted for some time to be able to loop over this sequence for different datasets, thus each time I would like to create a new MyNTupleLooper object, and new output, just as it would be if I just ran the macro twice for example.

But I have no idea how to delete the previous object here, a, and begin again. I always get the problem of histograms being replaced, even if I try to do something like this:

void mylooper(){
for(int it=0; it<path.size(); it++){

    gROOT->Reset();

    MyNTupleLooper *a = new MyNTupleLooper();
    a->AddFiles(path.at(it).c_str());
    a->Loop();

  
}
}

where path now is a vector object with the paths to my dataset-rootfiles (ntuples). I was hoping that to create the MyNTupleLooper object for each iteration again with new would be the solution, but obviously it is not.

Any suggestions are welcome

Thanks!

Maiken

2

Hi,

You need to make to delete the histogram and/or TFile in MyNTupleLooper::~MyNTupleLooper and call ‘delete a;’ in your loop.

Also to not call gROOT->Reset() from with a C++ function (it wipes the functions itself from being known by CINT …)

Cheers,
Philippe.

3

Thanks a lot for your reply.

I however still get the messages:

Warning in TROOT::Append: Replacing existing TH1: hMu_indet_neg_pt (Potential memory leak).
Warning in TROOT::Append: Replacing existing TH1: hMu_indet_neg_low_pt (Potential memory leak).
etc
etc…

which for me indicates that the object really is not deleted? I delete all the histograms in my looper class - what else can I do I wonder?

Maiken

4

Hi,

[quote]what else can I do I wonder[/quote]First you need to make sure you know where the histogram are coming from, they could come from either a ROOT file (via a TFile object), a TTree::Draw command, call to new TH1F or TH1D (etc.) or from some sub-routine you are calling. Then you need to make sure you call the delete operator on each of those.

Cheers,
Philippe.

5

Thank you very much, that worked nicely.

Maiken