diff options
Diffstat (limited to 'Source/FieldSolver/SpectralSolver/SpectralFieldData.cpp')
| -rw-r--r-- | Source/FieldSolver/SpectralSolver/SpectralFieldData.cpp | 67 |
1 files changed, 41 insertions, 26 deletions
diff --git a/Source/FieldSolver/SpectralSolver/SpectralFieldData.cpp b/Source/FieldSolver/SpectralSolver/SpectralFieldData.cpp index 31390127e..ca5e338e5 100644 --- a/Source/FieldSolver/SpectralSolver/SpectralFieldData.cpp +++ b/Source/FieldSolver/SpectralSolver/SpectralFieldData.cpp @@ -21,21 +21,32 @@ SpectralFieldData::SpectralFieldData( const BoxArray& realspace_ba, rho_old = SpectralField(spectralspace_ba, dm, 1, 0); rho_new = SpectralField(spectralspace_ba, dm, 1, 0); - // Allocate temporary arrays - over different boxarrays + // Allocate temporary arrays - in real space and spectral space + // These arrays will store the data just before/after the FFT tmpRealField = SpectralField(realspace_ba, dm, 1, 0); tmpSpectralField = SpectralField(spectralspace_ba, dm, 1, 0); - // Allocate the coefficients that allow to shift between nodal and cell-centered - xshift_C2N = k_space.getSpectralShiftFactor(dm, 0, ShiftType::CenteredToNodal); - xshift_N2C = k_space.getSpectralShiftFactor(dm, 0, ShiftType::NodalToCentered); + // By default, we assume the FFT is done from/to a nodal grid in real space + // It the FFT is performed from/to a cell-centered grid in real space, + // a correcting "shift" factor must be applied in spectral space. + xshift_FFTfromCell = k_space.getSpectralShiftFactor(dm, 0, + ShiftType::TransformFromCellCentered); + xshift_FFTtoCell = k_space.getSpectralShiftFactor(dm, 0, + ShiftType::TransformToCellCentered); #if (AMREX_SPACEDIM == 3) - yshift_C2N = k_space.getSpectralShiftFactor(dm, 1, ShiftType::CenteredToNodal); - yshift_N2C = k_space.getSpectralShiftFactor(dm, 1, ShiftType::NodalToCentered); - zshift_C2N = k_space.getSpectralShiftFactor(dm, 2, ShiftType::CenteredToNodal); - zshift_N2C = k_space.getSpectralShiftFactor(dm, 2, ShiftType::NodalToCentered); + yshift_FFTfromCell = k_space.getSpectralShiftFactor(dm, 1, + ShiftType::TransformFromCellCentered); + yshift_FFTtoCell = k_space.getSpectralShiftFactor(dm, 1, + ShiftType::TransformToCellCentered); + zshift_FFTfromCell = k_space.getSpectralShiftFactor(dm, 2, + ShiftType::TransformFromCellCentered); + zshift_FFTtoCell = k_space.getSpectralShiftFactor(dm, 2, + ShiftType::TransformToCellCentered); #else - zshift_C2N = k_space.getSpectralShiftFactor(dm, 1, ShiftType::CenteredToNodal); - zshift_N2C = k_space.getSpectralShiftFactor(dm, 1, ShiftType::NodalToCentered); + zshift_FFTfromCell = k_space.getSpectralShiftFactor(dm, 1, + ShiftType::TransformFromCellCentered); + zshift_FFTtoCell = k_space.getSpectralShiftFactor(dm, 1, + ShiftType::TransformToCellCentered); #endif // Allocate and initialize the FFT plans @@ -131,28 +142,30 @@ SpectralFieldData::ForwardTransform( const MultiFab& mf, fftw_execute( forward_plan[mfi] ); #endif - // Copy the spectral-space field `tmpSpectralField` to the appropriate field - // (specified by the input argument field_index ) + // Copy the spectral-space field `tmpSpectralField` to the appropriate + // field (specified by the input argument field_index ) + // and apply correcting shift factor if the real space data comes + // from a cell-centered grid in real space instead of a nodal grid. { SpectralField& field = getSpectralField( field_index ); Array4<Complex> field_arr = field[mfi].array(); Array4<const Complex> tmp_arr = tmpSpectralField[mfi].array(); - const Complex* xshift_C2N_arr = xshift_C2N[mfi].dataPtr(); + const Complex* xshift_arr = xshift_FFTfromCell[mfi].dataPtr(); #if (AMREX_SPACEDIM == 3) - const Complex* yshift_C2N_arr = yshift_C2N[mfi].dataPtr(); + const Complex* yshift_arr = yshift_FFTfromCell[mfi].dataPtr(); #endif - const Complex* zshift_C2N_arr = zshift_C2N[mfi].dataPtr(); + const Complex* zshift_arr = zshift_FFTfromCell[mfi].dataPtr(); // Loop over indices within one box const Box spectralspace_bx = tmpSpectralField[mfi].box(); ParallelFor( spectralspace_bx, [=] AMREX_GPU_DEVICE(int i, int j, int k) noexcept { Complex spectral_field_value = tmp_arr(i,j,k); // Apply proper shift in each dimension - if (is_nodal_x==false) spectral_field_value *= xshift_C2N_arr[i]; + if (is_nodal_x==false) spectral_field_value *= xshift_arr[i]; #if (AMREX_SPACEDIM == 3) - if (is_nodal_y==false) spectral_field_value *= yshift_C2N_arr[j]; + if (is_nodal_y==false) spectral_field_value *= yshift_arr[j]; #endif - if (is_nodal_z==false) spectral_field_value *= zshift_C2N_arr[k]; + if (is_nodal_z==false) spectral_field_value *= zshift_arr[k]; // Copy field into temporary array field_arr(i,j,k) = spectral_field_value; }); @@ -179,28 +192,30 @@ SpectralFieldData::BackwardTransform( MultiFab& mf, // Loop over boxes for ( MFIter mfi(mf); mfi.isValid(); ++mfi ){ - // Copy the appropriate field (specified by the input argument field_index) - // to the spectral-space field `tmpSpectralField` + // Copy the spectral-space field `tmpSpectralField` to the appropriate + // field (specified by the input argument field_index ) + // and apply correcting shift factor if the field is to be transformed + // to a cell-centered grid in real space instead of a nodal grid. { SpectralField& field = getSpectralField( field_index ); Array4<const Complex> field_arr = field[mfi].array(); Array4<Complex> tmp_arr = tmpSpectralField[mfi].array(); - const Complex* xshift_N2C_arr = xshift_N2C[mfi].dataPtr(); + const Complex* xshift_arr = xshift_FFTtoCell[mfi].dataPtr(); #if (AMREX_SPACEDIM == 3) - const Complex* yshift_N2C_arr = yshift_N2C[mfi].dataPtr(); + const Complex* yshift_arr = yshift_FFTtoCell[mfi].dataPtr(); #endif - const Complex* zshift_N2C_arr = zshift_N2C[mfi].dataPtr(); + const Complex* zshift_arr = zshift_FFTtoCell[mfi].dataPtr(); // Loop over indices within one box const Box spectralspace_bx = tmpSpectralField[mfi].box(); ParallelFor( spectralspace_bx, [=] AMREX_GPU_DEVICE(int i, int j, int k) noexcept { Complex spectral_field_value = field_arr(i,j,k); // Apply proper shift in each dimension - if (is_nodal_x==false) spectral_field_value *= xshift_N2C_arr[i]; + if (is_nodal_x==false) spectral_field_value *= xshift_arr[i]; #if (AMREX_SPACEDIM == 3) - if (is_nodal_y==false) spectral_field_value *= yshift_N2C_arr[j]; + if (is_nodal_y==false) spectral_field_value *= yshift_arr[j]; #endif - if (is_nodal_z==false) spectral_field_value *= zshift_N2C_arr[k]; + if (is_nodal_z==false) spectral_field_value *= zshift_arr[k]; // Copy field into temporary array tmp_arr(i,j,k) = spectral_field_value; }); |