Working in C++,making field of objects and sending them to other functions

[Vlado54564]

Hi everybody,I’m currently working in root,more precisely coding in C++.However I encountered a problem not long ago with grouping objects and trying to send them to another function…Getting a crash,so here is my code(there is also a file full of declarations,but I think this is all I need for explanation):

int main( int argc, char *argv[] )
{
Analyzer *Data = new Analyzer(0,“Data”);
Analyzer *ggTo4e = new Analyzer(0,“ggTo4e”);
Analyzer *ggTo2mu2tau = new Analyzer(0,“ggTo2mu2tau”);
Analyzer *VBFH125 = new Analyzer(0,“VBFH125”);
Analyzer *ZZTo4l = new Analyzer(0,“ZZTo4l”);
Analyzer *ggH125 = new Analyzer(0,“ggH125”);
Analyzer *WminusH125 = new Analyzer(0,“WminusH125”);
Analyzer *ggTo2e2mu = new Analyzer(0,“ggTo2e2mu”);
Analyzer *ggTo4mu = new Analyzer(0,“ggTo4mu”);
Analyzer *WplusH125 = new Analyzer(0,“WplusH125”);
Analyzer *ggTo2e2tau = new Analyzer(0,“ggTo2e2tau”);
Analyzer *ggTo4tau = new Analyzer(0,“ggTo4tau”);
Analyzer *ttH125 = new Analyzer(0,“ttH125”);
Analyzer *ZZH125 = new Analyzer(0,“ZZH125”);

Analysis->InitializeHistos();
Analysis->Loop();
Analysis->DrawHistos();
}

So I created 14 objects,now how do I send them to InitializeHistos(),Loop() and DrawHistos() function?
Thank u in advance

[yus]

Hi,

can you declare your objects in a header like

Analyzer *Data;
Analyzer *ggTo4e;
...

, keeping only the following in the main():

Data = new Analyzer(0, "Data");
ggT04e = new Analyzer(0, "ggto4e");
...

?

[Vlado54564]

Sure,what is my next step to sending those objects to functions then?

[yus]

You don’t need to send the objects to your functions, they are already allocated in the heap. For example, if you have

TH1F* data;

in a corresponding header, the following will work as expected:

#include "your_header.h"
int FillHisto()
{
        data->Fill(5, 1.);
        data->Fill(45, 3.);
        return 0;
}

int main(int argc, char** argv)
{
        TApplication app("test",&argc,argv);
        TCanvas *c = new TCanvas("c","Something",200,10,600,400);
        data = new TH1F("datahisto", "Data;X;Y", 50, 0., 50.);
        FillHisto();
        data->Draw();
        c->Modified(); c->Update();
        Int_t a; std::cin>>a; //prevents the window to close immediately
        return 0;
}

[ksmith]

I would avoid declaring things at global scope. It leads to headaches later when trying to expand the functionality of your code. I’d suggest something like the following:

int main( int argc, char *argv[] )
{
   std::map< std::string, Analyzer* > analyzers;
   analyzers.at("data") = new Analyzer(0,"Data");
   analyzers.at("ggTo4e") = new Analyzer(0,"ggTo4e");
   analyzers.at("ggTo2mu2tau") = new Analyzer(0,"ggTo2mu2tau");
   ...

   Analysis->InitializeHistos(analyzers);
   Analysis->Loop(analyzers);
   Analysis->DrawHistos(analyzers);
}

[Vlado54564]

Thank you on your help.
I think it might work ,however gotta fix few errors first.
At first it said program doesn’t recognize Analysis,so I changed it to Analyzer,as I should,but I get those
errors now:
///////////////////////////////////////////////////
run.cpp:39: error: expected unqualified-id before ‘->’ token
run.cpp:40: error: expected unqualified-id before ‘->’ token
run.cpp:41: error: expected unqualified-id before ‘->’ token

Those are the lines it is mentioning:

Analyzer->InitializeHistos(analyzers);
Analyzer->Loop(analyzers);
Analyzer->DrawHistos(analyzers);
////////////////////////////////////////////////////
Any ideas what is causing this error?