///////////////////////////////////////////////////////////////////////////////
//
///////////////////////////////////////////////////////////////////////////////

//_____________________________________________________________________________
TGraph*  cteq5l_glue_x_53(Double_t Q) {

  //  distribution for x^(5/3)*G(x,Q)

  int const np = 10000;
  double xx, x[np], y[np];

  double  uv, dv, usea, dsea, str, chrm, bot, top, glue;

  TCteq6* cteq6 = TCteq6::Instance();

  for (int i=0; i<np; i++) {
    xx  = (i+0.5)/np;
    x[i] = pow(xx,1./3);
    cteq6->Structm(xx,Q,uv,dv,usea,dsea,str,chrm,bot,top,glue);

    y[i] = pow(xx,2./3)*glue;

    //    printf(" x, y = %10.6f %10.6f \n",x[i],y[i]);
  }

  TGraph* gr = new TGraph(np,x,y);
  return gr;
}

//_____________________________________________________________________________
void test3(Double_t Q) {

  // check CTEQ5L: gluon  x^5/3*PDF

  TH2F* h = new TH2F("h_test3","CTEQ5L",10000,0,1.,1,0,0.4);
  h->GetXaxis()->SetTitle("X^{1/3}");

  char   parm[20][20];
  double val[20];

  strcpy(parm[0],"NPTYPE");
  parm[0][6] = ' ';
  val [0]    = 1;

  strcpy(parm[1],"NGROUP");
  parm[1][6] = ' ';
  val [1]    = 4;

  strcpy(parm[2],"NSET");
  parm[2][6] = ' ';
  val [2]    = 32;

  TCteq6* cteq6 = TCteq6::Instance();
  cteq6->Pdfset((const char*) parm,val);
  
  TGraph* gr_glue = cteq5l_glue_x_53(Q);

  h->Draw();

  gr_glue->Draw();
}