Reading and writing multiple files

ROOT
1

Hi, I’d like to know how I should go about to do the following (using a .C macro):

1- Open "File1.root"
2- Do some calculations
3- Write the results in an output file "Output.root"
4- Open “File2.root” and repeat previous steps (still using the same output file)

Thanks.

2

There is many examples here: https://root.cern/doc/master/group__Tutorials.html

3

Could you maybe point me to a particular tutorial, because I’ve had a look at them, and I can’t seem to find what I’m looking for.
Alternatively, could you write an example of code structure?

4

It looks like you mainly need help for the IO part. So the most appropriate tutorials will be:
https://root.cern/doc/master/group__tutorial__io.html

Basically you already have the code structure:

1- Open “File1.root” ==> Use TFile to open the file
2- Do some calculations ==> … up to you …
3- Write the results in an output file “Output.root” ==> Use TFile to open a new file and Write in it
4- Open “File2.root” and repeat previous steps (still using the same output file) ==> repeat what you just did.