Attilio,
In your 2nd script, do;
{
TFile miofile("Hfra40.root","read");
TH1F *hFra40;
TCanvas *c1 = (TCanvas*)miofile.Get("c1");
hFra40 = (TH1F*)c1->GetPrimitive("hFracEtcorr2Part");
c1->Clear();
c1->Draw();
hFra40->Draw();
}
or
{
TFile miofile("Hfra40.root","read");
TH1F *hFra40;
TCanvas *c1 = (TCanvas*)miofile.Get("c1");
hFra40 = (TH1F*)c1->GetPrimitive("hFracEtcorr2Part");
TCanvas c2;
hFra40->Draw();
}
In your original script, the current pad/canvas is c1.
So you draw the histogram in this canvas.
Rene Brun
Attilio Santocchia wrote:
>
> Hello
>
> I have the following problem: I wrote a canvas in a file and now I'd like to
> get back the histogram from the
> canvas and do some stuff...
> This is the 1st script:
>
> TFile miofile("Hfra40.root","read");
> miofile->ls();
> TCanvas *c1 = (TCanvas*)miofile.Get("c1");
> c1->Draw();
>
> the c1 canvas is drawn and this is the output:
> TFile** Hfra40.root
> TFile* Hfra40.root
> KEY: TCanvas c1;1 c1
>
> For now OK!
>
> This is the 2nd script:
>
> TFile miofile("Hfra40.root","read");
> TH1F *hFra40;
> TCanvas *c1 = (TCanvas*)miofile.Get("c1");
> hFra40 = (TH1F*)c1->GetPrimitive("hFracEtcorr2Part");
> hFra40->Draw();
>
> No error but no drawing -> not good (the name of the Histo is right!)
>
> 3th script:
>
> TFile miofile("Hfra40.root","read");
> TCanvas *c1 = (TCanvas*)miofile.Get("c1");
> TObject *obj;
> TIter next(c1->GetListOfPrimitives());
> while ((obj=next())) {
> cout << "Reading: " << obj->GetName() << endl;
> if (obj->InheritsFrom("TH1")) {
> cout << "histo: " << obj->GetName() << endl;
> }
> }
>
> the ouput of the script is:
>
> Reading: TFrame
> Reading: hFracEtcorr2Part
> histo: hFracEtcorr2Part
> Reading: title
>
> No error -> everything seems OK!
> but if I add the line
> obj->Draw();
> whitin the if statement... no drawing....
>
> Last script:
>
> TFile miofile("Hfra40.root","read");
> TCanvas *c1 = (TCanvas*)miofile.Get("c1");
> TObject *obj;
> TH1F *hFra40;
> TIter next(c1->GetListOfPrimitives());
> while ((obj=next())) {
> cout << "Reading: " << obj->GetName() << endl;
> if (obj->InheritsFrom("TH1")) {
> cout << "histo: " << obj->GetName() << endl;
> hFra40 = (TH1F*)obj->Clone();
> }
> }
> hFra40->Draw();
>
> again no error... but if I open a Tbroswser and get to the file (maybe this
> is the problem?) I see now the
> histogram with name hFracEtcorr2Part: try to double click on it to draw it
> and get this bunch of error:
> *** Break *** segmentation violation
> Generating stack trace...
> 0x40fb72f4 in TPad::PaintBox(double, double, double, double, char const*) +
> 0x37e from /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGpad.so
> 0x40fb637f in TPad::PaintBorder(short, bool) + 0xa1 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGpad.so
> 0x40fb6ba0 in TPad::PaintModified() + 0xd0 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGpad.so
> 0x40f9be04 in TCanvas::Update() + 0x78 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGpad.so
> 0x408152e3 in TH1::Browse(TBrowser*) + 0x3b from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libHist.so
> 0x412acf37 in TRootBrowser::IconBoxAction(TObject*) + 0x343 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x412ac497 in TRootBrowser::ProcessMessage(long, long, long) + 0xe39 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x4124f4b6 in TGFrame::HandleClientMessage(Event_t*) + 0x4a from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x41251a58 in TGMainFrame::HandleClientMessage(Event_t*) + 0x2c from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x4124f1ea in TGFrame::HandleEvent(Event_t*) + 0x1d0 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x41232f7b in TGClient::HandleEvent(Event_t*) + 0xd7 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x41232c74 in TGClient::ProcessOneEvent() + 0x6e from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x41232cfe in TGClient::HandleInput() + 0x28 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x4123187a in TGInputHandler::Notify() + 0x22 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libGui.so
> 0x401c643e in TUnixSystem::DispatchOneEvent(bool) + 0x3a from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libCore.so
> 0x401313b3 in TSystem::InnerLoop() + 0x25 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libCore.so
> 0x40131341 in TSystem::Run() + 0x7b from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libCore.so
> 0x400e19f6 in TApplication::Run(bool) + 0x30 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libCore.so
> 0x40e12bdb in TRint::Run(bool) + 0x311 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/lib/libRint.so
> 0x08048890 in main + 0x90 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/bin/root.exe
> 0x42017589 in __libc_start_main + 0x95 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/bin/root.exe
> 0x08048711 in _Unwind_Resume + 0x35 from
> /cms/external/lcg/external/root/3.10.01/rh73_gcc32/bin/root.exe
>
> Any suggestion on how to do?
>
> Thanks
>
> Attilio Santocchia
> Dipartimento di Fisica e INFN Perugia
> Tel.+39-075-5852708
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 05:50:09 MET