// Created by Paul Mullen (paulmullen66@gmail.com) August 2010
// mass_ana.C - EZCA and ROOT test macro
//
// An EPICS db was created to use with this example (Mass.db)
// record(ai, "mass_meas"){
//         field(DESC, "Measured mass")
//         field(PREC, "3")
// }
// Before running this example, start a softIoc with: 
// softIoc -s -m user=$USER -d Mass.db


#include <tsDefs.h>
#include <cadef.h>
#include <ezca.h>
#include <TFile.h>
#include <TH1F.h>
#include <TApplication.h>
#include <TCanvas.h>
#include <TF1.h>
#include <TMath.h>
#include <TStyle.h>

#include <iostream>
using namespace std;

Double_t gaussian(Double_t *x, Double_t *par)
{
  double arg = 0;
  if (par[2]) arg = (x[0] - par[1])/par[2];
  return par[0]*TMath::Exp(-0.5*arg*arg);
}

int main(int argc, char **argv){
   
   TApplication *theApp = new TApplication("MassAna", 0, NULL);
   gStyle->SetOptFit();

   char histfile[120];  
   sprintf(histfile, "%s", argv[1]);   
   printf("Opening file: %s ......... \n", histfile);
   TFile *hf1 = new TFile(histfile);
   TH1F *hist;
   hist = (TH1F *) hf1->Get("Mp");
   
   // Draw histogram
   TCanvas *canv=new TCanvas("canv");
   canv->cd();
   hist->Draw();  

   // Fit histogram and get mean
   TF1 *fitfunc = new TF1("fitfunc", gaussian, 0, 3, 3);
   fitfunc->SetParameters(10, hist->GetMean(), hist->GetRMS());
   fitfunc->SetParNames("A", "m_{meas}", "#sigma");
   hist->Fit("fitfunc"); 
   canv->Update(); 
   
   double m[1];
   m[0] = fitfunc->GetParameter(1);
   
   //Get a description of the variable we are going to set
   char desc[100];
   ezcaGet("mass_meas.DESC", ezcaString, 1, desc);
      
   printf("\nSetting '%s' to %5.3f in EPICS\n", desc, m[0]);
   ezcaPut("mass_meas.VAL", ezcaDouble, 1, m);
   
   theApp->Run();

   return 0;
}