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64 lines
1.5 KiB
Fortran
64 lines
1.5 KiB
Fortran
subroutine getcandidates4(id,fa,fb,syncmin,nfqso,maxcand,savg,candidate, &
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ncand,sbase)
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! For now, hardwired to find the largest peak in the average spectrum
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include 'ft2_params.f90'
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real s(NH1,NHSYM)
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real savg(NH1),savsm(NH1)
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real sbase(NH1)
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real x(NFFT1)
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complex cx(0:NH1)
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real candidate(3,maxcand)
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integer*2 id(NMAX)
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integer*1 s8(8)
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integer indx(NH1)
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data s8/0,1,1,1,0,0,1,0/
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equivalence (x,cx)
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! Compute symbol spectra, stepping by NSTEP steps.
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savg=0.
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tstep=NSTEP/12000.0
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df=12000.0/NFFT1 !3.125 Hz
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fac=1.0/300.0
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do j=1,NHSYM
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ia=(j-1)*NSTEP + 1
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ib=ia+NSPS-1
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x(1:NSPS)=fac*id(ia:ib)
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x(NSPS+1:)=0.
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call four2a(x,NFFT1,1,-1,0) !r2c FFT
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do i=1,NH1
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s(i,j)=real(cx(i))**2 + aimag(cx(i))**2
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enddo
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savg=savg + s(1:NH1,j) !Average spectrum
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enddo
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savsm=0.
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do i=2,NH1-1
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savsm(i)=sum(savg(i-1:i+1))/3.
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enddo
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nfa=fa/df
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nfb=fb/df
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np=nfb-nfa+1
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indx=0
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call indexx(savsm(nfa:nfb),np,indx)
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xn=savsm(nfa+indx(nint(0.3*np)))
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savsm=savsm/xn
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imax=-1
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xmax=-99.
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do i=2,NH1-1
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if(savsm(i).gt.savsm(i-1).and. &
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savsm(i).gt.savsm(i+1).and. &
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savsm(i).gt.xmax) then
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xmax=savsm(i)
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imax=i
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endif
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enddo
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f0=imax*df
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if(xmax.gt.1.2) then
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ncand=ncand+1
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candidate(1,ncand)=f0
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endif
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return
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end subroutine getcandidates4
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