/*
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#include "gmxpre.h"

#include <cmath>

#include "gromacs/commandline/pargs.h"
#include "gromacs/gmxana/gmx_ana.h"
#include "gromacs/gmxana/sfactor.h"
#include "gromacs/utility/arraysize.h"
#include "gromacs/utility/pleasecite.h"
#include "gromacs/utility/smalloc.h"

int gmx_saxs(int argc, char* argv[])
{
    const char* desc[] = { "[THISMODULE] calculates SAXS structure factors for given index",
                           "groups based on Cromer's method.",
                           "Both topology and trajectory files are required." };

    static real start_q = 0.0, end_q = 60.0, energy = 12.0;
    static int  ngroups = 1;

    t_pargs pa[] = {
        { "-ng", FALSE, etINT, { &ngroups }, "Number of groups to compute SAXS" },
        { "-startq", FALSE, etREAL, { &start_q }, "Starting q (1/nm) " },
        { "-endq", FALSE, etREAL, { &end_q }, "Ending q (1/nm)" },
        { "-energy", FALSE, etREAL, { &energy }, "Energy of the incoming X-ray (keV) " }
    };
#define NPA asize(pa)
    const char *      fnTPS, *fnTRX, *fnNDX, *fnDAT = nullptr;
    gmx_output_env_t* oenv;

    t_filenm fnm[] = {
        { efTRX, "-f", nullptr, ffREAD },     { efTPS, nullptr, nullptr, ffREAD },
        { efNDX, nullptr, nullptr, ffOPTRD }, { efDAT, "-d", "sfactor", ffOPTRD },
        { efXVG, "-sq", "sq", ffWRITE },
    };
#define NFILE asize(fnm)
    if (!parse_common_args(
                &argc, argv, PCA_CAN_TIME, NFILE, fnm, NPA, pa, asize(desc), desc, 0, nullptr, &oenv))
    {
        return 0;
    }

    fnTPS = ftp2fn(efTPS, NFILE, fnm);
    fnTRX = ftp2fn(efTRX, NFILE, fnm);
    fnDAT = ftp2fn(efDAT, NFILE, fnm);
    fnNDX = ftp2fn_null(efNDX, NFILE, fnm);

    do_scattering_intensity(
            fnTPS, fnNDX, opt2fn("-sq", NFILE, fnm), fnTRX, fnDAT, start_q, end_q, energy, ngroups, oenv);

    please_cite(stdout, "Cromer1968a");

    return 0;
}
