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Reference Guide
exec1.C File Reference

Detailed Description

Echo object at mouse position.

Example of macro called when a pad is redrawn one must create a TExec object in the following way

gPad->AddExec("ex1", ".x exec1.C");
#define gPad
Definition: TVirtualPad.h:288

this macro prints the bin number and the bin content when one clicks on the histogram contour of any histogram in a pad

void exec1()
{
if (!gPad) {
Error("exec1", "gPad is null, you are not supposed to run this macro");
return;
}
Int_t event = gPad->GetEvent();
int px = gPad->GetEventX();
TObject *select = gPad->GetSelected();
if (select && select->InheritsFrom(TH1::Class())) {
TH1 *h = (TH1*)select;
Float_t xx = gPad->AbsPixeltoX(px);
Float_t x = gPad->PadtoX(xx);
Int_t binx = h->GetXaxis()->FindBin(x);
printf("event=%d, hist:%s, bin=%d, content=%f\n", event, h->GetName(), binx, h->GetBinContent(binx));
}
}
#define h(i)
Definition: RSha256.hxx:106
int Int_t
Definition: RtypesCore.h:45
float Float_t
Definition: RtypesCore.h:57
void Error(const char *location, const char *msgfmt,...)
Use this function in case an error occurred.
Definition: TError.cxx:188
TH1 is the base class of all histogram classes in ROOT.
Definition: TH1.h:58
static TClass * Class()
Mother of all ROOT objects.
Definition: TObject.h:41
virtual Bool_t InheritsFrom(const char *classname) const
Returns kTRUE if object inherits from class "classname".
Definition: TObject.cxx:526
Double_t x[n]
Definition: legend1.C:17
Authors
Rene Brun, Sergey Linev

Definition in file exec1.C.