subroutine afc9(c3,npts,fsample,a,syncpk) complex c3(0:npts-1) real a(3),deltaa(3) a(1)=0. !f0 a(2)=0. !f1 a(3)=0. !f2 deltaa(1)=0.2 deltaa(2)=0.01 deltaa(3)=0.01 nterms=3 ! Start the iteration chisqr=0. chisqr0=1.e6 do iter=1,4 !One iteration is enough? do j=1,nterms chisq1=fchisq(c3,npts,fsample,a) fn=0. delta=deltaa(j) 10 a(j)=a(j)+delta 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 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 deltaa(j)=deltaa(j)*fn/3. ! write(*,4000) iter,j,a,deltaa,-chisq2 !4000 format(i1,i2,6f10.4,f9.3) enddo chisqr=fchisq(c3,npts,fsample,a) if(chisqr/chisqr0.gt.0.9999) exit chisqr0=chisqr enddo syncpk=-chisqr ! write(*,4001) a,deltaa,-chisq2 !4001 format(3x,6f10.4,f9.3) return end subroutine afc9