Textfile output

ROOT
1

Hi all,

Sorry for asking easy questions, I am quite new to this. I have a code that reads in a root file. Then calculate the number of scatters parallel and perpendicular to the beam line. When I run the code it outputs a root file which I open and I have a TH2F. I would also like a textfile which list the number of scatters in each direction. Is this possible? If so how?

I use these command in the code,

((TTreePlayer*)(tftree->GetPlayer()))->SetScanRedirect(true);
((TTreePlayer*)(tftree->GetPlayer()))->SetScanFileName(“output.txt”);
tftree->Scan(“proj_beam.proj_perp_beam”);

The textfile was created but looked like this (up to row 3059737)

  • Row * proj_beam *
  •    0 *           *

  •    1 *           *

  •    2 *           *

  •    3 *           *

  •    4 *           *

  •    5 *           *

  •    6 *           *

  •    7 *           *

  •    8 *           *

  •    9 *           *

  •   10 *           *

  •   11 *           *

  •   12 *           *

  •   13 *           *

  •   14 *           *

  •   15 *           *

This was the error message I get,

File <output.txt> created
Error in TTreeFormula::Compile: Bad numerical expression : “proj_beam.proj_perp_beam”

Thanks in advance, Chloe

2

Apparently “proj_beam.proj_perp_beam” does not exist in your TTree.
In order to see what’s available, try:
tftree->Print();
Note also, TH2F is NOT a TTree.

3

So now I have a macro that will output a textfile. I use the following commands,

root -l rootfile.root
root [0] .L outputtext.cpp
root [1] outputtext(myhist,“output.txt”)

But I get this error

Error: Symbol myhist is not defined in current scope (tmpfile):1:
*** Interpreter error recovered ***

This is what is loaded.

TFile** rootfile.root
TFile* rootfile.root
OBJ: TH2F myhist Perpendicular scatters -v- parallel scatters for all energies : 0 at: 0x105cb7bb0
KEY: TH2F myhist;1 Perpendicular scatters -v- parallel scatters for all energies

Can you someone tell me what I am doing wrong??

Thanks in advance, Chloe.

4

Before you use “myhist”, try to add:
TH2F *myhist = ((TH2F *)0);
gFile->GetObject(“myhist”, myhist);
or:
TH2F *myhist = ((TH2F *)(gROOT->FindObject(“myhist”)));

5

Do you mean into the code or command line?

6

root -l rootfile.root
root [0] TH2F *myhist = ((TH2F *)0);
root [1] gFile->GetObject(“myhist”, myhist);
root [2] .x outputtext.cpp(myhist, “output.txt”)

7

[quote=“Pepe Le Pew”]root -l rootfile.root
root [0] TH2F *myhist = ((TH2F *)0);
root [1] gFile->GetObject(“myhist”, myhist);
root [2] .x outputtext.cpp(myhist, “output.txt”)[/quote]

Thank you. I am now getting this error…

Error: Function outputtext(myhist,“output.txt”) is not defined in current scope :0:
*** Interpreter error recovered ***

8

outputtext.cpp

9

That is the command I ran

.x outputtext.cpp(myhist, “output.txt”)

and I still get the error

10

Then try your original two-step approach:
root [2] .L outputtext.cpp
root [3] outputtext(myhist, “output.txt”)

11

[quote=“Pepe Le Pew”]Then try your original two-step approach:
root [2] .L outputtext.cpp
root [3] outputtext(myhist, “output.txt”)[/quote]

Still the same error :frowning:

Error: Function outputtext(myhist,“output.txt”) is not defined in current scope (tmpfile):1:
*** Interpreter error recovered ***

12

So see what your “outputtext.cpp” file defines inside.

13

Solved!! :smiley: Turned out outputtext was defined as TH1F instead of TH2F. It is always something silly.

Thank you very much for all your help.

Chloe