doc/hackathon/hist021__TH2__reverse__axis_8C.html

void ReverseXAxis(TH1 *h);

void ReverseYAxis(TH1 *h);


void hist021_TH2_reverse_axis()

{

   TH2F *hpxpy = new TH2F("hpxpy", "py vs px", 40, -4, 4, 40, -4, 4);

   Float_t px, py;

   TRandom r;

   for (Int_t i = 0; i < 25000; i++) {

      r.Rannor(px, py);

      hpxpy->Fill(px, py);

   }

   TCanvas *c1 = new TCanvas("c1");

   hpxpy->Draw("colz");

   ReverseXAxis(hpxpy);

   ReverseYAxis(hpxpy);

}


void ReverseXAxis(TH1 *h)

{

   // Remove the current axis

   h->GetXaxis()->SetLabelOffset(999);

   h->GetXaxis()->SetTickLength(0);


   // Redraw the new axis

   gPad->Update();

   TGaxis *newaxis = new TGaxis(gPad->GetUxmax(), gPad->GetUymin(), gPad->GetUxmin(), gPad->GetUymin(),

                                h->GetXaxis()->GetXmin(), h->GetXaxis()->GetXmax(), 510, "-");

   newaxis->SetLabelOffset(-0.03);

   newaxis->Draw();

}


void ReverseYAxis(TH1 *h)

{

   // Remove the current axis

   h->GetYaxis()->SetLabelOffset(999);

   h->GetYaxis()->SetTickLength(0);


   // Redraw the new axis

   gPad->Update();

   TGaxis *newaxis = new TGaxis(gPad->GetUxmin(), gPad->GetUymax(), gPad->GetUxmin() - 0.001, gPad->GetUymin(),

                                h->GetYaxis()->GetXmin(), h->GetYaxis()->GetXmax(), 510, "+");

   newaxis->SetLabelOffset(-0.03);

   newaxis->Draw();

}

h
#define h(i)
Definition RSha256.hxx:106

Int_t
int Int_t
Signed integer 4 bytes (int).
Definition RtypesCore.h:59

Float_t
float Float_t
Float 4 bytes (float).
Definition RtypesCore.h:71

r
Option_t Option_t TPoint TPoint const char GetTextMagnitude GetFillStyle GetLineColor GetLineWidth GetMarkerStyle GetTextAlign GetTextColor GetTextSize void char Point_t Rectangle_t WindowAttributes_t Float_t r
Definition TGWin32VirtualXProxy.cxx:168

gPad
#define gPad
Definition TVirtualPad.h:322

TCanvas
The Canvas class.
Definition TCanvas.h:23

TGaxis
Definition TGaxis.h:26

TGaxis::SetLabelOffset
void SetLabelOffset(Float_t labeloffset)
Definition TGaxis.h:108

TH1
TH1 is the base class of all histogram classes in ROOT.
Definition TH1.h:109

TH2F
2-D histogram with a float per channel (see TH1 documentation)
Definition TH2.h:345

TObject::Draw
virtual void Draw(Option_t *option="")
Default Draw method for all objects.
Definition TObject.cxx:293

TRandom
This is the base class for the ROOT Random number generators.
Definition TRandom.h:27

c1
return c1
Definition legend1.C:41