Store TTree::Scan output into file

[eska]

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ROOT Version: 6.30.02
Platform: various
Compiler: various

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Hello,

I recently wanted to store the TTree::Scan output in a file and found that there were two approaches of doing so from the terminal (found here RE: Scan a TTree and put the output on a file from Philippe Canal on 2007-03-20 (RootTalk) ):

The TTreePlayer approach works fine, however the first (and simpler) one returns an error: use of undeclared identifier 'tree'

At first I thought this could be an outdated feature (the site is from 2007), but that method is also described here: Chapter: Trees, so I wonder if something is wrong on my end. Any help with this issue would be appreciated. Thanks a lot in advance.

[bellenot]

Try (for example):

root [0] auto file = TFile::Open("hsimple.root")
(TFile *) 0x1484ef9ffc0
root [1] ntuple->SetScanField(0)
root [2] .>scan_output.txt
root [3] ntuple->Scan()
root [4] .>
root [5]

And look at the scan_output.txt file in the current directory

[eska]

Thanks a lot for your reply!

This works indeed, however it also prints the command into the file. That is not a big issue, but I was wondering, is there is a way around that?

[bellenot]

Which command? I don’t see any command in the example I just posted. Here is the content of scan_output.txt:

************************************************************************
*    Row   *     px.px *     py.py *     pz.pz * random.ra *       i.i *
************************************************************************
*        0 * 0.0194094 * 0.0118254 * 0.0005165 * 0.2826178 *         0 *
*        1 * 0.3271895 * 0.0378782 * 0.1084877 * 0.4849736 *         1 *

[...]

*    24998 * -0.475986 * 2.0145735 * 4.2850694 * 0.5303411 *     24998 *
*    24999 * 1.5432313 * -0.102157 * 2.3919992 * 0.7472974 *     24999 *
************************************************************************
(long long) 25000

[eska]

I see. For me it writes also

e[0mroot [15] tree->Scan(e[De[0me[38;5;83me[1m()
e[0m

before the scan content is written

[bellenot]

OK, then I suppose it’s platform specific. I don’t know if we can do something about this…

[eska]

Okay I see, it shouldn’t be too big of an issue. Thanks for clarifying!