subroutine getcandidates4(id,fa,fb,syncmin,nfqso,maxcand,savg,candidate, & ncand,sbase) include 'ft4_params.f90' real s(NH1,NHSYM) real savg(NH1),savsm(NH1) real sbase(NH1) real x(NFFT1) real window(NFFT1) complex cx(0:NH1) real candidate(3,maxcand) integer*2 id(NMAX) integer indx(NH1) integer ipk(1) equivalence (x,cx) logical first data first/.true./ save first,window if(first) then first=.false. pi=4.0*atan(1.) window=0. call nuttal_window(window,NFFT1) endif ! Compute symbol spectra, stepping by NSTEP steps. savg=0. tstep=NSTEP/12000.0 df=12000.0/NFFT1 fac=1.0/300.0 do j=1,NHSYM ia=(j-1)*NSTEP + 1 ib=ia+NFFT1-1 if(ib.gt.NMAX) exit x=fac*id(ia:ib)*window call four2a(x,NFFT1,1,-1,0) !r2c FFT do i=1,NH1 s(i,j)=real(cx(i))**2 + aimag(cx(i))**2 enddo savg=savg + s(1:NH1,j) !Average spectrum enddo savsm=0. do i=8,NH1-7 savsm(i)=sum(savg(i-7:i+7))/15. enddo nfa=fa/df if(nfa.lt.1) nfa=1 nfb=fb/df if(nfb.gt.nint(5000.0/df)) nfb=nint(5000.0/df) n300=300/df n2500=2500/df ! np=nfb-nfa+1 np=n2500-n300+1 indx=0 call indexx(savsm(n300:n2500),np,indx) xn=savsm(n300+indx(nint(0.3*np))) ncand=0 if(xn.le.1.e-8) return savsm=savsm/xn ! call ft4_baseline(savg,nfa,nfb,sbase) ! savsm=savsm/sbase f_offset = -1.5*12000/512 do i=nfa+1,nfb-1 if(savsm(i).ge.savsm(i-1) .and. savsm(i).ge.savsm(i+1) .and. & savsm(i).ge.syncmin) then den=savsm(i-1)-2*savsm(i)+savsm(i+1) del=0. if(den.ne.0.0) del=0.5*(savsm(i-1)-savsm(i+1))/den fpeak=(i+del)*df+f_offset speak=savsm(i) - 0.25*(savsm(i-1)-savsm(i+1))*del ncand=ncand+1 if(ncand.gt.maxcand) then ncand=maxcand exit endif candidate(1,ncand)=fpeak candidate(2,ncand)=-99.99 candidate(3,ncand)=speak if(ncand.eq.maxcand) exit endif enddo return end subroutine getcandidates4