Macro for producing Log(Rate) vs. Threshold

plotThresh.C

/****************************************************************************
 * Macro to plot log(Rate) vs. Threshold plots. 
 *
 * Usage: in root...
 * 		.x plotThresh.C
 *
 * Author: Brian Freeman 
 * Date: 11/6/14
 ***************************************************************************/
  
#include <iostream>
#include <fstream>

#include <string>
using namespace std;

//arrays that will be used in the TGraphErrors plot
Double_t thresholds[25];
Double_t rate[25];
Double_t events[25];
Double_t delta_t[25];
Double_t dx[25];
Double_t dy[25];

//i is the array index
Int_t i=0;


//main method
void plotThresh(){
      
   /*********************
    * Get file contents 
    *********************/
    
   //The file path goes here. My files were named tube[1-4].dat 
   //and located in the data directory
   std::ifstream f(  "../data/threshold.dat" );	
		 
   //loop through the file stopping when there are nomore lines in the file
   for( std::string line; getline( f, line );){
			
	//the line is taken in, and variables assigned and inserted into data arrays
	std::istringstream( line )>>thresholds[i]>>delta_t[i]>>events[i]>>dx[i]>>dy[i]; 
			
	rate[i] =  log10( events[i] / delta_t[i] ) ;

	//increment the index
	i++;
   }
   //close file resources
   f.close();
   f.clear();
    
   /**************
   * Plot data
   **************/ 
    
   //create canvas
   TCanvas *c1 = new TCanvas("threshold","Log(Rate) vs Threshold",400,400,600,600);
   //set options
   gStyle->SetOptStat(1); 
   gStyle->SetOptFit(1);  
   c1->ToggleEventStatus(); 
	
   //create single graphs   
    
   //using the arrays that I built from the data file
   TGraphErrors *g = new TGraphErrors(1000 , thresholds , rate , dx, dy );	
   g = new TGraphErrors(i , thresholds , rate , dx, dy);
   g->SetLineColor(2);//red
   g->SetMarkerColor(2);//red
   g->SetMarkerStyle(21);//square
 
   //draw title 
   g->SetTitle("Log(Rate) vs. Threshold");
	
   //draw graph
   g->Draw("AP"); 
    
   //plot labels
   g->GetYaxis()->SetTitle("Log(Rate) [log(Hz)]");
   g->GetXaxis()->SetTitle("Threshold [mV]"); 

}//end of main