Running a C++ Script in ROOT

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1

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ROOT Version: root_v6.19.02.macosx64-10.15-clang110.tar.gz
Platform: Mac OS
Compiler: XCode

Hi I am running through a root tutorial for my lab. I tried making a C++ script to open a file and make histograms as well as a .root file.

Can anyone let me know what I did wrong in my code.

First here is my script.

oot_v6.19.02.macosx64-10.15-clang110.tar.gz

#include "/Users/conor/root/macros/exo_j2.C"
#include "Riostream.h"
#include "TFile.h"
#include "TH1.h"
#include "TNtuple.h"

void exo_j2(const Char_t* fdata="exo_j2.data", const Char_t* froot="exo_j2.root")
{
    
   ifstream in;

   open(fdata, ios::in);

   Float_t x,y,z,e;
   Int_t nlines = 0;

   TFile *f = new TFile(froot,"exo_j2.root");

    TH1F *hz = new TH1F("hz","z distribution",100,-10,10);
    TH2F *hy_hx = new TH2F("hy_hx","Y vs X",100,-25,25,100,-25,25);
    TH2F *hz_hx = new TH2F("hz_hx","Z vs X)",100,-10,10,100,-25,25);
    TH2F *hz_hy = new TH2F("hz_hy","Z vs X)",100,-10,10,100,-25,25);
    //TProfile *hxprof = new TProfile("profx","<e> vs X",100,-25,25);
    //TProfile *hyprof = new TProfile("profx","<e> vs X",100,-25,25);
    TH3F *hx_hy_hz = new TH3F("hx_hy_hz","Z vs Y vs X",100,-25,25,100,-25,25,100,-10,10);
    TNtuple *ntuple = new TNtuple("ntuple","data from ascii file","x:y:z:e");


   while (in.good())
    {
      in >> x >> y >> z >> e;
      if (in.good())
       {
       if (nlines < 5)
        {
        cout << "X =  " << x << ", Y =  " << y ;
        cout << ",Z =   " << z << ",E = " << e << endl;
        }
       hz->Fill(z);
           hy_hx->Fill(x,y);
           hz_hx->Fill(x,z);
           hz_hy->Fill(y,z);
           //hxprof->Fill(x,e,1);
           //hyprof->Fill(y,e,1);
       ntuple->Fill(x,y,z,e);
       nlines++;
       }
    };
   in.close();

   f->Write();
   delete f;
}

Here are the errors I received after running the script.

**/Users/conor/root/macros/exo_j2.C:23:4:** **error:** **unknown type name 'TFile'**

TFile *f = new TFile(froot,"exo_j2.root");

**^**

**/Users/conor/root/macros/exo_j2.C:23:19:** **error:** **unknown type name 'TFile'**

TFile *f = new TFile(froot,"exo_j2.root");

**^**

**/Users/conor/root/macros/exo_j2.C:25:5:** **error:** **unknown type name 'TH1F'**

TH1F *hz = new TH1F("hz","z distribution",100,-10,10);

**^**

**/Users/conor/root/macros/exo_j2.C:25:20:** **error:** **unknown type name 'TH1F'**

TH1F *hz = new TH1F("hz","z distribution",100,-10,10);

**^**

**/Users/conor/root/macros/exo_j2.C:26:5:** **error:** **unknown type name 'TH2F'**

TH2F *hy_hx = new TH2F("hy_hx","Y vs X",100,-25,25,100,-25,25);

**^**

**/Users/conor/root/macros/exo_j2.C:26:23:** **error:** **unknown type name 'TH2F'**

TH2F *hy_hx = new TH2F("hy_hx","Y vs X",100,-25,25,100,-25,25);

**^**

**/Users/conor/root/macros/exo_j2.C:27:5:** **error:** **unknown type name 'TH2F'**

TH2F *hz_hx = new TH2F("hz_hx","Z vs X)",100,-10,10,100,-25,25);

**^**

**/Users/conor/root/macros/exo_j2.C:27:23:** **error:** **unknown type name 'TH2F'**

TH2F *hz_hx = new TH2F("hz_hx","Z vs X)",100,-10,10,100,-25,25);

**^**

**/Users/conor/root/macros/exo_j2.C:28:5:** **error:** **unknown type name 'TH2F'**

TH2F *hz_hy = new TH2F("hz_hy","Z vs X)",100,-10,10,100,-25,25);

**^**

**/Users/conor/root/macros/exo_j2.C:28:23:** **error:** **unknown type name 'TH2F'**

TH2F *hz_hy = new TH2F("hz_hy","Z vs X)",100,-10,10,100,-25,25);

**^**

**/Users/conor/root/macros/exo_j2.C:31:5:** **error:** **unknown type name 'TH3F'**

TH3F *hx_hy_hz = new TH3F("hx_hy_hz","Z vs Y vs X",100,-25,25,100,-25,2...

**^**

**/Users/conor/root/macros/exo_j2.C:31:26:** **error:** **unknown type name 'TH3F'**

TH3F *hx_hy_hz = new TH3F("hx_hy_hz","Z vs Y vs X",100,-25,25,100,-25,2...

It seems to be not recognizing the TH3F types. Unsure how to fix this issue.

2

Hi,
does that first #include statement include the script itself?

Cheers,
Enrico

4

For including the script do I need to specify its file path or just the name of the script as well as the data file?

5

Hi Conor,
including it where exactly? The script definitely does not need to #include itself. To run the script from ROOT, assuming a working ROOT installation you can just run root /Users/conor/root/macros/exo_j2.C from your command line.

With more information (what you tried, what you expected to happen, what actually happened, and steps to reproduce the situation myself) I might be of more help.

Cheers,
Enrico

6

So I am expecting to create a new root file exo_j2.root with the following histograms hz, hy_hz, hz_hx, hz_hy, and hx_hy_hz. I am using the command line to open root and then from in root I give the command .L exo_j2.c to load the script and then execute it. I have removed the include from the start of the script. I then try to open open the new file in the TBrowser but I do not see it existing. Attached are the script file and the data file in a txt format. exo_j2.c (1.3 KB) exo_j2.txt (658.4 KB)

7

It’s .x exo_j2.c to execute the function in the file with the same name of the file. Otherwise .L exo_j2.c followed by, e.g. exo_j2() to actually execute the function. Are you sure the function is executed (you can e.g. add a std::cout << "i'm executing!" << std::endl; inside)?

Also looking at your script you need to open the file in “recreate” mode, new TFile(froot, "recreate")

8

TFile *f = TFile::Open(froot, "RECREATE");

1 Like
9

So it now makes the histograms but for some reason they are empty. Thank you for your help.

11

Yeah I can see that it is executing but its not filling from the file.

12

in.open(fdata, ios::in);

13

Where did I go wrong with that line?