HistWriter.cc

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/**
  @file   HistWriter.cc
  Defines the HistWriter class.
  @author Daniel Abercrombie <dabercro@mit.edu>
*/

#include <fstream>
#include <iostream>
#include "TFile.h"
#include "TH1F.h"
#include "TH2F.h"

#include "HistWriter.h"

ClassImp(HistWriter)

//--------------------------------------------------------------------
HistWriter::HistWriter(TString fileName, TString histName) :
  fFileName(fileName),
  fHistName(histName)
{ }

//--------------------------------------------------------------------
HistWriter::~HistWriter()
{ }

//--------------------------------------------------------------------

/**
   Reads the configuration file given by configName. The configuration
   file consists only of alternating bin edge locations and bin contents.
   The first and last number of the file should be a bin edge.
   (The number of edges is the number of bins + 1).
   These can be separated by spaces or new lines.
*/

void HistWriter::MakeHist(TString configName)
{
  std::vector<Float_t> xVals;
  std::vector<Float_t> binVals;

  std::ifstream configFile;
  configFile.open(configName.Data());
  TString xVal;
  TString binVal;
  Bool_t reading = true;
  while (reading) {
    configFile >> xVal >> binVal;
    xVals.push_back(xVal.Atof());
    if (binVal != "")
      binVals.push_back(binVal.Atof());
    else
      reading = false;
  }

  TFile* outFile = new TFile(fFileName, "UPDATE");
  TH1F*  outHist = new TH1F(fHistName, fHistName, binVals.size(), xVals.data());

  for (UInt_t iBin = 0; iBin != binVals.size(); ++iBin)
    outHist->SetBinContent(iBin + 1, binVals[iBin]);

  outFile->WriteTObject(outHist, fHistName, "Overwrite");
  outFile->Close();

  configFile.close();
}

void HistWriter::Make2DHist(TString configName, unsigned numX, unsigned numY)
{
  if (not numX or not numY)
    exit(40);

  std::vector<Float_t> xVals;
  std::vector<Float_t> yVals;
  std::vector<Float_t> binVals;

  std::ifstream configFile;
  configFile.open(configName.Data());
  TString axisVal;
  TString binVal;
  // Read X values
  for (unsigned xBin = 0; xBin < numX; xBin++) {
    configFile >> axisVal;
    xVals.push_back(axisVal.Atof());
  }

  Bool_t reading = true;
  while (reading) {
    configFile >> axisVal;
    yVals.push_back(axisVal.Atof());

    for (unsigned xBin = 1; xBin < numX; xBin++) {
      configFile >> binVal;
      if (binVal != "")
        binVals.push_back(binVal.Atof());
      else {
        reading = false;
        break;
      }
    }
  }

  TFile* outFile = new TFile(fFileName, "UPDATE");
  TH2F*  outHist = new TH2F(fHistName, fHistName, numX - 1, xVals.data(), numY - 1, yVals.data());

  for (UInt_t xBin = 1; xBin < numX; ++xBin) {
    for (UInt_t yBin = 1; yBin < numY; ++yBin)
      outHist->SetBinContent(xBin, yBin, binVals[xBin - 1 + (numX - 1) * (yBin - 1)]);
  }

  outFile->WriteTObject(outHist, fHistName, "Overwrite");
  outFile->Close();

  configFile.close();
}