Line data    Source code

       1             : MODULE m_fft3d
       2             : CONTAINS
       3        2986 :    SUBROUTINE fft3d(&
       4        2986 :   &                 afft, bfft, fg3,&
       5             :   &                 stars, isn, scaled)
       6             : 
       7             : !************************************************************
       8             : !*                                                          *
       9             : !* interface for fg3(star) -- FFT --> (a,b)fft (r) (isn=+1) *
      10             : !*         or (a,b)fft (r) -- FFT --> fg3(star)    (isn=-1) *
      11             : !*                                                          *
      12             : !* dimension of (a,b)fft is (3*k1d x 3*k2d x 3*k3d)         *
      13             : !* afft and bfft contain the real/imaginary part of the FFT *
      14             : !* igfft(i,1) is the pointer from the G-sphere to stars     *
      15             : !* igfft(i,2) is the pointer from the G-sphere to fft-grid  *
      16             : !* pgfft(i)   contains the phases of the G-vectors of sph.  *
      17             : !*                                                          *
      18             : !************************************************************
      19             :       USE m_types
      20             :       USE m_types_fftGrid
      21             :       IMPLICIT none
      22             : 
      23             :       INTEGER, INTENT(IN)       :: isn
      24             :       TYPE(t_stars), INTENT(IN) :: stars
      25             :       REAL, INTENT(INOUT)       :: afft(:)
      26             :       REAL, INTENT(INOUT)       :: bfft(:)
      27             :       COMPLEX                   :: fg3(stars%ng3) !Sometimes we call this with an intent(in) variable if isn>0 (This is somewhat unsafe)
      28             :       LOGICAL, INTENT(IN), OPTIONAL :: scaled ! < determines if coefficients are scaled by stars%nstr
      29             : 
      30       23888 :       TYPE(t_fftgrid) :: fftgrid
      31       11944 :       call fftgrid%init((/3*stars%mx1,3*stars%mx2,3*stars%mx3/))
      32             : 
      33        2986 :       IF (isn > 0) THEN
      34        1174 :           call fftgrid%putFieldOnGrid(stars,fg3)
      35             :       ELSE 
      36    68214048 :          fftgrid%grid=cmplx(afft,bfft)
      37             :       ENDIF       
      38             :      
      39        2986 :       call fftgrid%perform_fft(forward=(isn<0))
      40             : !---> now do the fft (isn=+1 : G -> r ; isn=-1 : r -> G)
      41             : 
      42        2986 :       if (isn >0) THEN
      43    44163130 :         afft = real(fftgrid%grid)
      44    44163130 :         bfft = aimag(fftgrid%grid)
      45             :       else
      46        1812 :          call fftgrid%takeFieldFromGrid(stars,fg3)
      47             :          !Scaling by stars%nstr is already done in previous call
      48        1812 :          IF (PRESENT(scaled)) THEN
      49           0 :             IF (.not.scaled) fg3 = fg3*stars%nstr
      50             :          ENDIF
      51             :       ENDIF   
      52             : 
      53        2986 :    END SUBROUTINE fft3d
      54             : END MODULE m_fft3d