TScatter2D.cxx

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// @(#)root/hist:$Id$
// Author: Olivier Couet   23/09/2025
 
/*************************************************************************
 * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
 
#include "TROOT.h"
#include "TScatter2D.h"
#include "TH1.h"
#include "TVirtualGraphPainter.h"
 
#include <iostream>
 
 
////////////////////////////////////////////////////////////////////////////////
 
/** \class TScatter2D
    \ingroup Graphs
A TScatter2D is able to draw five variables scatter plot on a single plot. The three first
variables are the x, y and z position of the markers (stored in a TGraph2D), the fourth is
mapped on the current color map and the fifth on the marker size.
 
The following example demonstrates how it works:
 
Begin_Macro(source)
../../../tutorials/visualisation/graphs/gr019_scatter2d.C
End_Macro
 
### TScatter2D's plotting options
TScatter2D can be drawn with the following options:
 
| Option   | Description                                                       |
|----------|-------------------------------------------------------------------|
| "SAME"   | Superimpose on previous picture in the same pad.|
| "LOGC"   | Log scale for colors.|
| "LOGS"   | Log scale for sizes.|
| "FB"     | Suppress the Front-Box.|
| "BB"     | Suppress the Back-Box.|
| "A"      | Suppress the axis.|
| "P"      | Suppress the palette.|
 
In the case of the SAME option, the log scale for color and size is inherited from the
previously drawn TScatter2D. For example, if a TScatter2D is drawn on top of another one
that uses a log scale for color, the second TScatter2D will also use a log scale for its
colors, even if the log scale for color is not explicitly specified for the second plot.
 
*/
 
 
////////////////////////////////////////////////////////////////////////////////
/// TScatter2D default constructor.
 
TScatter2D::TScatter2D()
{
}
 
////////////////////////////////////////////////////////////////////////////////
/// TScatter2D normal constructor.
///
///  the arrays are preset to zero
 
TScatter2D::TScatter2D(Int_t n)
{
   fGraph     = new TGraph2D(n);
   fNpoints   = fGraph->GetN();
 
   fColor = new Double_t[fNpoints];
   fSize  = new Double_t[fNpoints];
 
   memset(fColor, 0, fNpoints * sizeof(Double_t));
   memset(fSize, 0, fNpoints * sizeof(Double_t));
   fMaxMarkerSize = 5.;
   fMinMarkerSize = 1.;
   fMargin = 0.1;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// TScatter2D normal constructor.
 
TScatter2D::TScatter2D(Int_t n, Double_t *x, Double_t *y, Double_t *z, const Double_t *col, const Double_t *size)
{
   Bool_t status = TH1::AddDirectoryStatus();
   TH1::AddDirectory(kFALSE);
   fGraph     = new TGraph2D(n, x, y, z);
   fNpoints   = fGraph->GetN();
 
   Int_t bufsize = sizeof(Double_t) * fNpoints;
   if (col) {
      fColor = new Double_t[fNpoints];
      memcpy(fColor, col, bufsize);
   }
   if (size) {
      fSize  = new Double_t[fNpoints];
      memcpy(fSize, size, bufsize);
   }
 
   fMaxMarkerSize = 5.;
   fMinMarkerSize = 1.;
   fMargin = 0.1;
 
   TH1::AddDirectory(status);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// TScatter2D default destructor.
 
TScatter2D::~TScatter2D()
{
   delete fGraph;
   delete [] fColor;
   delete [] fSize;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Compute distance from point px,py,pz to a scatter plot.
///
///  Compute the closest distance of approach from point px,py,pz to this scatter plot.
///  The distance is computed in pixels units.
 
Int_t TScatter2D::DistancetoPrimitive(Int_t px, Int_t py)
{
   Int_t distance = 9999;
   if (fGraph) distance = fGraph->DistancetoPrimitive(px, py);
   return distance;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Execute action corresponding to one event.
///
///  This member function is called when a graph is clicked with the locator
///
///  If Left button clicked on one of the line end points, this point
///     follows the cursor until button is released.
///
///  if Middle button clicked, the line is moved parallel to itself
///     until the button is released.
 
void TScatter2D::ExecuteEvent(Int_t event, Int_t px, Int_t py)
{
   if (fGraph) fGraph->ExecuteEvent(event, px, py);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Returns a pointer to the histogram used to draw the axis
 
TH2D *TScatter2D::GetHistogram() const
{
   if (fGraph) return fGraph->GetHistogram();
   else return nullptr;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Get the scatter's x axis.
 
TAxis *TScatter2D::GetXaxis() const
{
   if (fGraph) return fGraph->GetXaxis();
   else return nullptr;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Get the scatter's y axis.
 
TAxis *TScatter2D::GetYaxis() const
{
   if (fGraph) return fGraph->GetYaxis();
   else return nullptr;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Get the scatter's z axis.
 
TAxis *TScatter2D::GetZaxis() const
{
   if (fGraph) return fGraph->GetZaxis();
   else return nullptr;
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Paint this scatter plot with its current attributes.
 
void TScatter2D::Paint(Option_t *option)
{
   TVirtualGraphPainter *painter = TVirtualGraphPainter::GetPainter();
   if (painter) painter->PaintScatter2D(this, option);
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Print graph and errors values.
 
void TScatter2D::Print(Option_t *) const
{
   if (!fGraph) return;
 
   Double_t *X = fGraph->GetX();
   Double_t *Y = fGraph->GetY();
   Double_t *Z = fGraph->GetZ();
   for (Int_t i = 0; i < fNpoints; i++) {
      printf("x[%d]=%g, y[%d]=%g, z[%d]=%g", i, X[i], i, Y[i], i, Z[i]);
      if (fColor) printf(", color[%d]=%g", i, fColor[i]);
      if (fSize) printf(", size[%d]=%g", i, fSize[i]);
      printf("\n");
   }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Set the margin around the plot in %
 
void TScatter2D::SetMargin(Double_t margin)
{
   if (fMargin != margin) {
      fMargin = margin;
   }
}
 
 
////////////////////////////////////////////////////////////////////////////////
/// Save primitive as a C++ statement(s) on output stream out
 
void TScatter2D::SavePrimitive(std::ostream &out, Option_t *option /*= ""*/)
{
   TString arr_x    = SavePrimitiveVector(out, "scat_x", fNpoints, fGraph->GetX(), kTRUE);
   TString arr_y    = SavePrimitiveVector(out, "scat_y", fNpoints, fGraph->GetY());
   TString arr_z    = SavePrimitiveVector(out, "scat_z", fNpoints, fGraph->GetZ());
   TString arr_col  = SavePrimitiveVector(out, "scat_col", fNpoints, fColor);
   TString arr_size = SavePrimitiveVector(out, "scat_size", fNpoints, fSize);
 
   SavePrimitiveConstructor(out, Class(), "scat",
                            TString::Format("%d, %s.data(), %s.data(), %s.data(), %s.data(), %s.data()", fNpoints, arr_x.Data(),
                                            arr_y.Data(), arr_z.Data(), arr_col.Data(), arr_size.Data()),
                            kFALSE);
 
   SavePrimitiveNameTitle(out, "scat");
   SaveFillAttributes(out, "scat", 0, 1001);
   SaveLineAttributes(out, "scat", 1, 1, 1);
   SaveMarkerAttributes(out, "scat", 1, 1, 1);
 
   out << "   scat->SetMargin(" << GetMargin() << ");\n";
   out << "   scat->SetMinMarkerSize(" << GetMinMarkerSize() << ");\n";
   out << "   scat->SetMaxMarkerSize(" << GetMaxMarkerSize() << ");\n";
 
   SavePrimitiveDraw(out, "scat", option);
}