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/*! \libinternal
 * \file
 * \brief
 * Declares routine for computing many correlation functions using OpenMP
 *
 * \author David van der Spoel <david.vanderspoel@icm.uu.se>
 * \inlibraryapi
 * \ingroup module_correlationfunctions
 */
#ifndef GMX_MANYAUTOCORRELATION_H
#define GMX_MANYAUTOCORRELATION_H

#include <vector>

#include "gromacs/fft/fft.h"
#include "gromacs/utility/real.h"

/*! \brief
 * Perform many autocorrelation calculations.
 *
 * This routine performs many autocorrelation function calculations using FFTs.
 * The GROMACS FFT library wrapper is employed. On return the c vector contain
 * a symmetric function that is useful for further FFT:ing, for instance in order to
 * compute spectra.
 *
 * The vectors c[i] should all have the same length, but this is not checked for.
 *
 * The c arrays will be extend and filled with zero beyond ndata before
 * computing the correlation.
 *
 * The functions uses OpenMP parallellization.
 *
 * \param[inout] c Data array
 * \return fft error code, or zero if everything went fine (see fft/fft.h)
 * \throws gmx::InconsistentInputError if the input is inconsistent.
 */
int many_auto_correl(std::vector<std::vector<real>>* c);

#endif
