subroutine afc9(c3a,npts,fsample,a,syncpk) complex c3a(0:npts-1) complex c3(0:1360-1) real a(3),deltaa(3) a(1)=0. !f0 a(2)=0. !f1 a(3)=0. !f2 deltaa(1)=1.736 deltaa(2)=1.736 deltaa(3)=1.0 nterms=3 ! Start the iteration chisqr=0. chisqr0=1.e6 c3=c3a a3=a(3) do iter=1,4 do j=1,nterms if(a(3).ne.a3) call shft(c3a,a(3),a3,c3) chisq1=fchisq(c3,npts,fsample,a) fn=0. delta=deltaa(j) 10 a(j)=a(j)+delta if(a(3).ne.a3) call shft(c3a,a(3),a3,c3) chisq2=fchisq(c3,npts,fsample,a) if(chisq2.eq.chisq1) go to 10 if(chisq2.gt.chisq1) then delta=-delta !Reverse direction a(j)=a(j)+delta tmp=chisq1 chisq1=chisq2 chisq2=tmp endif 20 fn=fn+1.0 a(j)=a(j)+delta if(a(3).ne.a3) call shft(c3a,a(3),a3,c3) chisq3=fchisq(c3,npts,fsample,a) if(chisq3.lt.chisq2) then chisq1=chisq2 chisq2=chisq3 go to 20 endif ! Find minimum of parabola defined by last three points delta=delta*(1./(1.+(chisq1-chisq2)/(chisq3-chisq2))+0.5) a(j)=a(j)-delta if(j.lt.3) deltaa(j)=deltaa(j)*fn/3. ! write(*,4000) iter,j,a,-chisq2 !4000 format(i1,i2,3f10.4,f11.3) enddo if(a(3).ne.a3) call shft(c3a,a(3),a3,c3) chisqr=fchisq(c3,npts,fsample,a) if(chisqr/chisqr0.gt.0.99) exit chisqr0=chisqr enddo syncpk=-chisqr c3a=c3 ! write(*,4001) a,-chisq2 !4001 format(3x,3f10.4,f11.3) return end subroutine afc9 subroutine shft(c3a,a3a,a3,c3) complex c3a(0:1359) complex c3(0:1359) a3=a3a n=nint(a3) c3=cshift(c3a,n) if(n.gt.0) c3(1360-n:)=0.0 if(n.lt.0) c3(:n-1)=0.0 return end subroutine shft