tab_calc_fftw3_real_fwd Subroutine

public subroutine tab_calc_fftw3_real_fwd(tab_in, tab_ou, long, larg)

Note

Subroutine that transforms forward a real array. For speed reasons FFTW will always work on the same memory area, until the plans are destroyed of course. several FFT on single thread each

Arguments

Type IntentOptional Attributes Name
real(kind=R8), intent(in), dimension(1:long, 1:larg) :: tab_in

array to transform
complex(kind=R8), intent(out), dimension(1:long, 1:larg) :: tab_ou

transformed array
integer(kind=I4), intent(in) :: long

first 2D array dimension
integer(kind=I4), intent(in) :: larg

second 2D array dimension

Calls

proc~~tab_calc_fftw3_real_fwd~~CallsGraph proc~tab_calc_fftw3_real_fwd tab_calc_fftw3_real_fwd interface~fftw_execute_dft_r2c fftw_execute_dft_r2c proc~tab_calc_fftw3_real_fwd->interface~fftw_execute_dft_r2c omp_get_thread_num omp_get_thread_num proc~tab_calc_fftw3_real_fwd->omp_get_thread_num

Called by

proc~~tab_calc_fftw3_real_fwd~~CalledByGraph proc~tab_calc_fftw3_real_fwd tab_calc_fftw3_real_fwd program~test_fftw3 test_fftw3 program~test_fftw3->proc~tab_calc_fftw3_real_fwd

Source Code

   subroutine tab_calc_fftw3_real_fwd(tab_in, tab_ou, long, larg)
   implicit none
   integer(kind=I4), intent(in ) :: long                                !! *first  2D array dimension*
   integer(kind=I4), intent(in ) :: larg                                !! *second 2D array dimension*
   real   (kind=R8), dimension(1:long, 1:larg), intent(in ) :: tab_in   !! *array to transform*
   complex(kind=R8), dimension(1:long, 1:larg), intent(out) :: tab_ou   !! *transformed array*

      integer(kind=I4) :: ithread

      ithread = omp_get_thread_num()

      tab_rea_f_i(ithread)%tab(1:long, 1:larg) = tab_in(1:long, 1:larg)

      call fftw_execute_dft_r2c(tab_plan_f(ithread), tab_rea_f_i(ithread)%tab(1:long, 1:larg),   &  !
                                                     tab_cmp_f_o(ithread)%tab(1:long, 1:larg))      !

      tab_ou(1:long, 1:larg) = tab_cmp_f_o(ithread)%tab(1:long, 1:larg) / sqrt(real(long*larg, kind=r8))

   return
   endsubroutine tab_calc_fftw3_real_fwd