! (C) Copyright 2000- ECMWF. ! (C) Copyright 2000- Meteo-France. ! ! This software is licensed under the terms of the Apache Licence Version 2.0 ! which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. ! In applying this licence, ECMWF does not waive the privileges and immunities ! granted to it by virtue of its status as an intergovernmental organisation ! nor does it submit to any jurisdiction. ! MODULE FTDIRAD_MOD CONTAINS SUBROUTINE FTDIRAD(PREEL,KFIELDS,KGL) !**** *FTDIRAD - Direct Fourier transform ! Purpose. Routine for Grid-point to Fourier transform - adjoint ! -------- !** Interface. ! ---------- ! CALL FTDIRAD(..) ! Explicit arguments : PREEL - Fourier/grid-point array ! -------------------- KFIELDS - number of fields ! Method. ! ------- ! Externals. FFTW - FFT routine ! ---------- ! ! Author. ! ------- ! Mats Hamrud *ECMWF* ! Modifications. ! -------------- ! Original : 00-03-03 ! D. Degrauwe (Feb 2012): Alternative extension zone (E') ! G. Mozdzynski (Oct 2014): support for FFTW transforms ! G. Mozdzynski (Jun 2015): Support alternative FFTs to FFTW ! R. El Khatib 08-Jun-2023 LALL_FFTW for better flexibility ! ------------------------------------------------------------------ USE PARKIND1 ,ONLY : JPIM, JPRB USE TPM_DISTR ,ONLY : D, MYSETW USE TPM_GEOMETRY ,ONLY : G USE TPM_FFTW ,ONLY : TW, EXEC_FFTW USE TPM_DIM ,ONLY : R IMPLICIT NONE INTEGER(KIND=JPIM),INTENT(IN) :: KFIELDS,KGL REAL(KIND=JPRB), INTENT(INOUT) :: PREEL(:,:) INTEGER(KIND=JPIM) :: IGLG,IST,ILEN,JJ,JF,ILOEN INTEGER(KIND=JPIM) :: IOFF,IRLEN,ICLEN,ITYPE REAL(KIND=JPRB) :: ZMUL ! ------------------------------------------------------------------ ITYPE = 1 IGLG = D%NPTRLS(MYSETW)+KGL-1 IST = 2*(G%NMEN(IGLG)+1)+1 ILOEN = G%NLOEN(IGLG)+R%NNOEXTZL ILEN = ILOEN+3-IST IOFF = D%NSTAGTF(KGL)+1 IRLEN = ILOEN ICLEN = (IRLEN/2+1)*2 DO JJ=1,ILEN DO JF=1,KFIELDS PREEL(JF,IST+IOFF-1+JJ-1) = 0.0_JPRB ENDDO ENDDO CALL EXEC_FFTW(ITYPE,IRLEN,ICLEN,IOFF,KFIELDS,TW%LALL_FFTW,PREEL) ! Change of metric (not in forward routine) ZMUL = 1.0_JPRB/ILOEN DO JJ=1,ILOEN DO JF=1,KFIELDS PREEL(JF,IOFF-1+JJ) = PREEL(JF,IOFF-1+JJ)*ZMUL ENDDO ENDDO ! ------------------------------------------------------------------ END SUBROUTINE FTDIRAD END MODULE FTDIRAD_MOD