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C Copyright 1981-2016 ECMWF.
C
C This software is licensed under the terms of the Apache Licence
C Version 2.0 which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
C
C In applying this licence, ECMWF does not waive the privileges and immunities
C granted to it by virtue of its status as an intergovernmental organisation
C nor does it submit to any jurisdiction.
C
program fftw
implicit none
integer n
integer m
integer i
integer j
parameter (n=2*2*3*5)
parameter (m=20)
real a ((n+2)*m)
real trigs (n)
real work (m*(n+1))
integer ifax (10)
#include "fftw3.f"
integer*8 plan
integer KLONO
integer JPLONO
real del
real angle
real PZFA((n+2)*m)
real FFTWOUT(n)
REAL PPI
PARAMETER ( PPI = 3.14159265358979 )
C Generate sines and cosines for angles 0 to pi in N steps
C (possibly the only surviving part of set99)
del = (2.0*ppi) / float(n)
do i = 0, (n/2)-1
angle = float(i)*del
trigs(2*i+1) = cos(angle)
trigs(2*i+2) = sin(angle)
enddo
call set99(trigs,ifax,n)
a = 0
do j = 1, m
do i = 1, n
a((j-1)*(n+2)+i) = j
enddo
enddo
call fft99(a,work,trigs,ifax,1,n+2,n,m,-1)
KLONO = n
JPLONO = n
PZFA = a
FFTWOUT(1:KLONO) = 0.
CALL DFFTW_PLAN_DFT_C2R_1D( PLAN, KLONO, PZFA, FFTWOUT,
. FFTW_ESTIMATE
.+ FFTW_UNALIGNED
.+ FFTW_NO_SIMD )
CALL DFFTW_EXECUTE( PLAN )
PZFA( 1:KLONO ) = FFTWOUT(1:KLONO)
PZFA( KLONO+1:(JPLONO+2)*m ) = 0.
a = PZFA
CALL DFFTW_DESTROY_PLAN( PLAN )
write (*,'(4(f20.12,2x))') (a(i),i=1,n)
end
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