mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-12-18 00:48:36 -05:00
09ceb60a4e
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@3296 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
91 lines
2.7 KiB
Fortran
91 lines
2.7 KiB
Fortran
subroutine four2a(a,nfft,ndim,isign,iform)
|
|
|
|
! IFORM = 1, 0 or -1, as data is
|
|
! complex, real, or the first half of a complex array. Transform
|
|
! values are returned in array DATA. They are complex, real, or
|
|
! the first half of a complex array, as IFORM = 1, -1 or 0.
|
|
|
|
! The transform of a real array (IFORM = 0) dimensioned N(1) by N(2)
|
|
! by ... will be returned in the same array, now considered to
|
|
! be complex of dimensions N(1)/2+1 by N(2) by .... Note that if
|
|
! IFORM = 0 or -1, N(1) must be even, and enough room must be
|
|
! reserved. The missing values may be obtained by complex conjugation.
|
|
|
|
! The reverse transformation of a half complex array dimensioned
|
|
! N(1)/2+1 by N(2) by ..., is accomplished by setting IFORM
|
|
! to -1. In the N array, N(1) must be the true N(1), not N(1)/2+1.
|
|
! The transform will be real and returned to the input array.
|
|
|
|
parameter (NPMAX=100)
|
|
parameter (NSMALL=16384)
|
|
complex a(nfft)
|
|
complex aa(NSMALL)
|
|
integer nn(NPMAX),ns(NPMAX),nf(NPMAX)
|
|
integer*8 plan(NPMAX),nl(NPMAX),nloc
|
|
data nplan/0/,npatience/1/
|
|
! data nplan/0/,npatience/0/
|
|
include 'fftw3.f90'
|
|
save plan,nplan,nn,ns,nf,nl
|
|
|
|
if(nfft.lt.0) go to 999
|
|
|
|
nloc=loc(a)
|
|
do i=1,nplan
|
|
if(nfft.eq.nn(i) .and. isign.eq.ns(i) .and. &
|
|
iform.eq.nf(i) .and. nloc.eq.nl(i)) go to 10
|
|
enddo
|
|
if(nplan.ge.NPMAX) stop 'Too many FFTW plans requested.'
|
|
nplan=nplan+1
|
|
i=nplan
|
|
nn(i)=nfft
|
|
ns(i)=isign
|
|
nf(i)=iform
|
|
nl(i)=nloc
|
|
|
|
! Planning: FFTW_ESTIMATE, FFTW_ESTIMATE_PATIENT, FFTW_MEASURE,
|
|
! FFTW_PATIENT, FFTW_EXHAUSTIVE
|
|
nflags=FFTW_ESTIMATE
|
|
if(npatience.eq.1) nflags=FFTW_ESTIMATE_PATIENT
|
|
if(npatience.eq.2) nflags=FFTW_MEASURE
|
|
if(npatience.eq.3) nflags=FFTW_PATIENT
|
|
if(npatience.eq.4) nflags=FFTW_EXHAUSTIVE
|
|
|
|
if(nfft.le.NSMALL) then
|
|
jz=nfft
|
|
if(iform.eq.0) jz=nfft/2
|
|
do j=1,jz
|
|
aa(j)=a(j)
|
|
enddo
|
|
endif
|
|
if(isign.eq.-1 .and. iform.eq.1) then
|
|
call sfftw_plan_dft_1d(plan(i),nfft,a,a,FFTW_FORWARD,nflags)
|
|
else if(isign.eq.1 .and. iform.eq.1) then
|
|
call sfftw_plan_dft_1d(plan(i),nfft,a,a,FFTW_BACKWARD,nflags)
|
|
else if(isign.eq.-1 .and. iform.eq.0) then
|
|
call sfftw_plan_dft_r2c_1d(plan(i),nfft,a,a,nflags)
|
|
else if(isign.eq.1 .and. iform.eq.-1) then
|
|
call sfftw_plan_dft_c2r_1d(plan(i),nfft,a,a,nflags)
|
|
else
|
|
stop 'Unsupported request in four2a'
|
|
endif
|
|
i=nplan
|
|
if(nfft.le.NSMALL) then
|
|
jz=nfft
|
|
if(iform.eq.0) jz=nfft/2
|
|
do j=1,jz
|
|
a(j)=aa(j)
|
|
enddo
|
|
endif
|
|
|
|
10 continue
|
|
call sfftw_execute(plan(i))
|
|
return
|
|
|
|
999 do i=1,nplan
|
|
! The test is only to silence a compiler warning:
|
|
if(ndim.ne.-999) call sfftw_destroy_plan(plan(i))
|
|
enddo
|
|
|
|
return
|
|
end subroutine four2a
|