LHAPDF is hosted by Hepforge, IPPP Durham
LHAPDF  6.2.1
/examples/testpdf.cc
// Program to test LHAPDF6 PDF behaviour by writing out their values at lots of x and Q points
// Note: the OpenMP directives are there as an example. In fact, in this case OpenMP slows things
// down because of the need to make the stream operations critical!
#include "LHAPDF/LHAPDF.h"
#include <iostream>
#include <fstream>
using namespace LHAPDF;
using namespace std;
int main(int argc, char* argv[]) {
if (argc < 3) {
cerr << "You must specify a PDF set and member number" << endl;
return 1;
}
const string setname = argv[1];
const string smem = argv[2];
const int imem = lexical_cast<int>(smem);
const PDF* pdf = mkPDF(setname, imem);
vector<int> pids = pdf->flavors();
const double MINLOGX = -10;
const double MAXLOGX = 0;
const double DX = 0.01;
const int NX = (int) floor((MAXLOGX - MINLOGX)/DX) + 1;
const double MINLOGQ2 = 1;
const double MAXLOGQ2 = 8;
const double DQ2 = 0.01;
const int NQ2 = (int) floor((MAXLOGQ2 - MINLOGQ2)/DQ2) + 1;
for (int pid : pids) {
const string spid = lexical_cast<string>(pid);
const string filename = setname + "_" + smem + "_" + spid + ".dat";
ofstream f(filename.c_str());
for (int ix = 0; ix < NX; ++ix) {
const double log10x = (MINLOGX + ix*DX < -1e-3) ? MINLOGX + ix*DX : 0;
const double x = pow(10, log10x);
for (int iq2 = 0; iq2 < NQ2; ++iq2) {
const double log10q2 = MINLOGQ2 + iq2*DQ2;
const double q2 = pow(10, log10q2);
const double xf = pdf->xfxQ2(pid, x, q2);
f << x << " " << q2 << " " << xf << endl;
}
}
f.close();
}
for (double log10q2 = MINLOGQ2; log10q2 <= MAXLOGQ2; log10q2 += 0.2) {
const double q2 = pow(10, log10q2);
cout << "alpha_s(" << setprecision(1) << fixed << sqrt(q2) << " GeV) = "
<< setprecision(5) << pdf->alphasQ2(q2) << endl;
}
delete pdf;
return 0;
}