void test_macro()//arguements:th1, th2, y axis max
{
   gStyle->SetNdivisions(510,"X");
   gStyle->SetNdivisions(505,"Y");
   gStyle->SetStatBorderSize(1);
   gStyle->SetStatW(0.2);
   gStyle->SetStatH(0.1);
   gStyle->SetCanvasBorderMode(0);
   gStyle->SetPadBorderMode(0);
   gStyle->SetCanvasColor(0);
   gStyle->SetFrameBorderMode(0);
   gStyle->SetPadColor(0);
   gStyle->SetStatColor(0);
   gStyle->SetLabelSize(.06,"xy");
   gStyle->SetLabelOffset(.011,"xy");
   gStyle->SetTitleXOffset(1.1);
   gStyle->SetTitleXSize(0.06);
   gStyle->SetTitleYOffset(1.12);
   gStyle->SetTitleYSize(0.06);
   gStyle->SetTitleW(0.5);
   gStyle->SetTitleH(0.08);
   gStyle->SetTitleBorderSize(1);
   gStyle->SetTitleFillColor(0);
   gStyle->SetPadLeftMargin(0.18);
   gStyle->SetPadRightMargin(0.15);
   gStyle->SetPadBottomMargin(.18);
   gStyle->SetTextSize(.03);
   gStyle->SetStatFontSize(.03);
   gStyle->SetOptStat(11);
   gStyle->SetOptTitle(0);
   gStyle->SetPalette(1);

   Int_t TH1 = 16, TH2 =16;
   TGraph *tg1, *tg2, *tg3, *tg4;
   int nn1 = 0, nn2 = 0;
   float kB1[5500], kB2[5500], kB3[5500], kB4[5500], kB5[5500];

   char line[256], cc1[1], kHash1[1], buff1[256], ch1, cc2[1], kHash2[1], buff2[256], ch2;
   float var1a, var2a, var3a, var4a, var5a;
   float var1b, var2b, var3b, var4b, var5b;
   float sigma1[200], ss1[200], ed1[200], ep1[200], en1[200];
   float sigma2[200], ss2[200], ed2[200], ep2[200], en2[200];
   float ee1, th1a, th2a, phi12a, dummy1a;
   float ee2, th1b, th2b, phi12b, dummy1b;
   int points1, dummy2a, dummy3a;
   int points2, dummy2b, dummy3b;
   //###########
   //read a text file
   //fill vectors
   //plot TGraphError
   //save it as png file
   char file1[500], file2[500];
   char text1[500];
   float kS1, kCounts1, kNorm;
   float kS[200], kS_err[200], kCounts[200];
   float kSQRT_count1;
   float kSQRT_count[200];
   FILE *pfile, *pfile1, *pfile2;
   TGraphErrors *tg;
   int k1[49], k2[49];
   float k3[49], k4[49];
   int kk1, kk2;
   float kk3, kk4;
   int m1[49], m2[49];
   float m3[49], m4[49];
   int mm1, mm2;
   float mm3, mm4;
   float deltaS = 4.0;
   float tot_effi_d[7], tot_effi_p[7];

   //normalising factor:
   float n_el[7] = {1465730, 793332, 502017, 371621, 279511, 259465, 239448};
   float dOhm_p[7] = {0.0605, 0.0678, 0.0750, 0.0822, 0.0892, 0.0961, 0.1030};
   float sigma_el[7] = {7.5, 3.55, 2.0, 1.38, 1.02, 0.78, 0.62};
   float effi_dE[7]={0.9980, 0.9981, 0.9982, 0.9982, 0.9984, 0.9984, 0.9981};
   float effi_MWPC_D[7]={0.8698, 0.8759, 0.8739, 0.8712, 0.8768, 0.8719, 0.8761};//for deuterons
   float effi_MWPC_P[7]={0.8496, 0.8533, 0.8484, 0.8484, 0.8499, 0.8642, 0.8539};//for protons
   float effi_cross_over_el[7]={0.9929, 0.9938, 0.9898, 0.9915, 0.9937, 0.9936, 0.9902};//from elastic d simulation
   float effi_conf[7][7];
   float effi_cross_over_br[7][7];//for breakup configurations
   int TriggReScale = 32; // to scale back the single trigg events of el d
   int micro2mili = 1000;//convert the elastic cro-sec from micro to mili barn (because theory is in mili)
   float nonrel2rel = 3.0;//approximate conversion from non-reltivistic theory to relativistic (in MeV)
   kNorm = 1.0;
   sprintf(file1,"S_bg_sub_thd%d_thp%d_fi180.dat", TH1, TH2);//WITH BACKGROUND SUB.
   int n = 0;
   pfile = fopen(file1,"r");
   while (true) {
      fscanf(pfile," %f %f %f", &kS1, &kCounts1, &kSQRT_count1);
      if (feof(pfile)) break;
      kS[n] = kS1;
      kS_err[n] = 0;
      kCounts[n] = kCounts1/kNorm;
      kSQRT_count[n] = kSQRT_count1/kNorm;
      n++;
   }

   tg = new TGraphErrors(n, kS, kCounts, kS_err, kSQRT_count);
   tg->SetMarkerColor(kOrange);
   tg->SetMarkerStyle(21);
   tg->SetMarkerSize(1.0);
   tg->GetXaxis()->SetTitle("S [MeV]");
   tg->GetYaxis()->SetTitle("#frac{d^{5}#sigma}{dSd#Omega_{1}d#Omega_{2}} [#mub#upointsr^{-2}#upointMeV^{-1}]");
   tg->GetXaxis()->CenterTitle();
   tg->GetYaxis()->CenterTitle();
   float gunn = 20.0;

   TCanvas *can1 = new TCanvas ("can1","can1",700,450);
   Float_t ymax_my = 1.0;

   //   can1->cd();
   tg->Draw("AP");
   TAxis *axis = tg->GetXaxis();
   axis->SetLimits(20.,190.);                         // along X
   tg->GetHistogram()->SetMaximum(ymax_my);    // along
   tg->GetHistogram()->SetMinimum(0);   //    Y

   sprintf(text1,"#it{#theta_{p}}=%d#circ", TH2);

   TPaveText *pt1=new TPaveText(0.2,0.8,0.4,0.85,"NDC");
   pt1->SetFillColor(0);
   pt1->AddText(text1);
   pt1->SetBorderSize(0);
   pt1->SetTextFont(82);
   pt1->SetTextSize(0.05);
   pt1->SetTextColor(1);
   pt1->Draw();

   can1->Modified();
   can1->Update();

   Float_t rightmax = ymax_my*gunn;
   TGaxis *right_axis = new TGaxis(gPad->GetUxmax(),gPad->GetUymin(),gPad->GetUxmax(), gPad->GetUymax(),0,rightmax,505,"+L");
   right_axis->SetLineColor(kRed);
   right_axis->SetTextColor(kRed);
   right_axis->SetTitle("neutron energy [MeV]");
   right_axis->SetTitleSize(0.06);
   right_axis->CenterTitle();
   right_axis->SetLabelOffset(0.008);
   right_axis->SetTextFont(82);
   right_axis->SetLabelFont(82);
   right_axis->SetLabelSize(0.06);
   right_axis->SetLabelColor(kRed);
   right_axis->SetTitleOffset(0.9);
   right_axis->Draw();

   can1->SaveAs(Form("S_thd%d_thp%d_fi180.png", TH1, TH2));
}