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#ifndef WARPX_SPECTRAL_SOLVER_H_
#define WARPX_SPECTRAL_SOLVER_H_
#include <SpectralKSpace.H>
#include <PsatdAlgorithm.H>
#include <SpectralFieldData.H>
/* \brief Top-level class for the electromagnetic spectral solver
*
* Stores the field in spectral space, and has member functions
* to Fourier-transform the fields between real space and spectral space
* and to update fields in spectral space over one time step.
*/
class SpectralSolver
{
public:
// Inline definition of the member functions of `SpectralSolver`
// The body of these functions is short, since the work is done in the
// underlying classes `SpectralFieldData` and `PsatdAlgorithm`
/* \brief Initialize the spectral solver */
SpectralSolver( const amrex::BoxArray& realspace_ba,
const amrex::DistributionMapping& dm,
const int norder_x, const int norder_y,
const int norder_z, const bool nodal,
const amrex::RealVect dx, const amrex::Real dt ) {
// Initialize all structures using the same distribution mapping dm
// - Initialize k space object (Contains info about the size of
// the spectral space corresponding to each box in `realspace_ba`,
// as well as the value of the corresponding k coordinates)
const SpectralKSpace k_space= SpectralKSpace(realspace_ba, dm, dx);
// - Initialize the algorithm (coefficients) over this space
algorithm = PsatdAlgorithm( k_space, dm, norder_x, norder_y,
norder_z, nodal, dt );
// - Initialize arrays for fields in Fourier space + FFT plans
field_data = SpectralFieldData( realspace_ba, k_space, dm );
};
/* \brief Transform the component `i_comp` of MultiFab `mf`
* to spectral space, and store the corresponding result internally
* (in the spectral field specified by `field_index`) */
void ForwardTransform( const amrex::MultiFab& mf,
const int field_index,
const int i_comp=0 ){
BL_PROFILE("SpectralSolver::ForwardTransform");
field_data.ForwardTransform( mf, field_index, i_comp );
};
/* \brief Transform spectral field specified by `field_index` back to
* real space, and store it in the component `i_comp` of `mf` */
void BackwardTransform( amrex::MultiFab& mf,
const int field_index,
const int i_comp=0 ){
BL_PROFILE("SpectralSolver::BackwardTransform");
field_data.BackwardTransform( mf, field_index, i_comp );
};
/* \brief Update the fields in spectral space, over one timestep */
void pushSpectralFields(){
BL_PROFILE("SpectralSolver::pushSpectralFields");
algorithm.pushSpectralFields( field_data );
};
private:
SpectralFieldData field_data; // Store field in spectral space
// and perform the Fourier transforms
PsatdAlgorithm algorithm; // Contains Psatd coefficients
// and field update equation
};
#endif // WARPX_SPECTRAL_SOLVER_H_
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