How to save numbers to binary/txt file?

Hi I’m quite new to TProof. Everything is working very well with TObject.
However, I want to save numbers from TTree to binary/txt file based on some cuts .
How can I pass the result to output list? I tried with

  1. simple declare class member, vector, doesn’t work.
  2. TVectorT, doesn’t work.
  3. TH1D, have to choose number of bins, bin width, so lose precision of the number or lose some numbers out of range.

Is there any TObject holding double like vector?
Or can I save to file in the Process()?

I know it’s quite naive question but I just could find on the google or here.

I create my own class inhered from TNamed and finally get the number.
But if you root expert have some more handy solution, please let me know.