82 lines
1.9 KiB
Plaintext
82 lines
1.9 KiB
Plaintext
|
subroutine afc9(c3a,npts,fsample,a,syncpk)
|
||
|
|
|
||
|
|
parameter (NZ2=1512)
|
||
|
|
complex c3a(0:NZ2-1)
|
||
|
|
complex c3(0:NZ2-1)
|
||
|
|
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)
|
||
|
|
! write(*,4000) 0,0,a,-chisqr
|
||
|
|
if(chisqr/chisqr0.gt.0.99) exit
|
||
|
|
chisqr0=chisqr
|
||
|
|
enddo
|
||
|
|
|
||
|
|
syncpk=-chisqr
|
||
|
|
c3a=c3
|
||
|
|
! write(*,4001) a,syncpk
|
||
|
|
!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
|