Converting histograms stored in root files to .png's

[salina]

I have written TH1F histograms to a root file within a script (TFile *f = new Tfile(“check.root”, “recreate”)) and I am trying to find a way to not go through each histogram in the root file and “save” it. Is there a way to export these root files either within the script or another script and save it as a .png? I did not draw these histograms to a TCanvas in my script, and I am trying to avoid doing so which is why I wrote it to a root file in the first place. I understand that .root files are not graphical, but is there still a way? Any help or suggestion will be much appreciated!

[amvargash]

List of all histograms in a file

First comment: In my installation I found loopdir.C at $ROOTSYS/tutorials/loopdir.C I am using 5.13/02. Second comment: I have a root file with a subdirectory which has many histograms which can be seen in TBrowser. I find that when I use the keys method I only get the key for the subdirectory. The keys to the histograms are never returned. It would seem that I need to set my directory to the subdirectory and then fetch the keys. I tried this with this code: TFile *f = new TFile(“T0C…

[Wile_E_Coyote]

If you use ROOT 6, try:
ls `root-config --bindir`/root*
rootprint --help

[sbinet]

and if you’re on Windows (so, stuck w/ ROOT-5):

you can also use:

• https://godoc.org/go-hep.org/x/hep/rootio/cmd/root-print

(it also works for Linux, macOS, *BSDs, …)

[salina]

I am using root 6.6.08… this is what happens when I try to use this “rootprint”:

Traceback (most recent call last):
  File "/usr/local/root/bin/rootprint", line 10, in <module>
    import cmdLineUtils
ImportError: No module named cmdLineUtils

and I’m on a mac OS x… note that this error also happens via root 5 (using root-print)

[amvargash]

If you’re on CSH, Try:

setenv PYTHONPATH $ROOTSYS/lib:${PYTHONPATH}

EDIT: Shell Corrected

[sbinet]

are you sure you are using “my” root-print command?

that can’t be the case as go-hep/rootio doesn’t use python.

[sbinet]

if on bash, that should read:

$> export PYTHONPATH=$ROOTSYS/lib:$PYTHONPATH