// $Id$
//-----------------------------------------------------------------------
//       The GSI Online Offline Object Oriented (Go4) Project
//         Experiment Data Processing at EE department, GSI
//-----------------------------------------------------------------------
// Copyright (C) 2000- GSI Helmholtzzentrum fuer Schwerionenforschung GmbH
//                     Planckstr. 1, 64291 Darmstadt, Germany
// Contact:            http://go4.gsi.de
//-----------------------------------------------------------------------
// This software can be used under the license agreements as stated
// in Go4License.txt file which is part of the distribution.
//-----------------------------------------------------------------------

#include "TGo4RollingGraph.h"

#include "TMath.h"

/** \brief Default constructor
 *
 * Creates a rolling graph with an update interval of 1, i.e. no averaging of the input values
 * Graph will have no size, either. Without setting size, nothing will be drawn!
 */
TGo4RollingGraph::TGo4RollingGraph()
   : TGraphErrors(), fiNumPoints(0), fiUpdateInterval(1), fiCounter(0), fdSum(0.), fdSumAveraged(0.)
{
}

/** \brief Constructor with size and update interval
 * \param NumPoints Size of the graph, i.e. number of points
 * \param UpdateInterval No. of calls to the Fill() routine after which a new bin will started to be filled. For
 * UpdateInterval=1 every value will be displayed directly on the rolling graph, for values > 1 an average will be shown
 */
TGo4RollingGraph::TGo4RollingGraph(Int_t NumPoints, Int_t UpdateInterval)
   : TGraphErrors(), fiNumPoints(NumPoints), fiUpdateInterval(UpdateInterval), fiCounter(0), fdSum(0.),
     fdSumAveraged(0.)
{
}

/** \brief Destructor */
TGo4RollingGraph::~TGo4RollingGraph()
{
}

/** \brief Fills a new value into the rolling graph
* \param value The value to fill
* \param xerror The X value
* \param yerror The Y value
*
* If the Update Interval is larger than one, the value will not be displayed directly in the graph but added to the averaging
*/
void TGo4RollingGraph::Fill(Double_t value, Double_t xerror, Double_t yerror)
{
   if (fiNumPoints)
   {
      Int_t NumAverage = fiCounter % fiUpdateInterval + 1;
      // Create a new bin and reset internal value for averaging if counter is a multiple of fiUpdateInterval
      if (NumAverage == 1)
      {
         NextBin();
         fdSum = 0.;
      }

      // Add value for averaging
      fdSum += value;
      fdSumAveraged = fdSum / static_cast<Double_t>(NumAverage);

      // Draw new averaged value
      SetPoint(fNpoints-1, static_cast<Double_t>(fiCounter / fiUpdateInterval), fdSumAveraged);
      if (xerror < 0)
         xerror = 0.5;
      if (yerror < 0)
         yerror = fdSumAveraged / TMath::Sqrt(NumAverage);
      SetPointError(fNpoints-1, xerror, yerror);
   }
   fiCounter++;
}

/** \brief Create a new bin
*
* Internal function that implements the "rolling" of the graph: The first bin is deleted while a new one is appended at the end
*/
void TGo4RollingGraph::NextBin()
{
   if (fiNumPoints)
   {
      if (fiNumPoints <= fNpoints)
      {
         // Move points to the left
         memmove (&fX[0],  &fX[1],  (fNpoints-1)*sizeof(Double_t));
         memmove (&fEX[0], &fEX[1], (fNpoints-1)*sizeof(Double_t));
         memmove (&fY[0],  &fY[1],  (fNpoints-1)*sizeof(Double_t));
         memmove (&fEY[0], &fEY[1], (fNpoints-1)*sizeof(Double_t));
      }
      else
      {
         // Create a new point
         Set(fNpoints+1);
      }
   }
}

/** \brief Clear all points
*
* Remove all points from the graph, set number of points to zero, and reset internal value for averaging
*/
void TGo4RollingGraph::Clear(Option_t *)
{
   for (Int_t i = 0; i < fiNumPoints; ++i)
      RemovePoint(i);

   Set(0);
   fdSum = 0.;
}