mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-05 08:51:19 -05:00
e3bafe053b
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/map65@1011 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
70 lines
1.9 KiB
Fortran
70 lines
1.9 KiB
Fortran
subroutine afc65b(cx,cy,npts,fsample,nflip,ipol,a,dt0,
|
|
+ ccfbest,dtbest)
|
|
|
|
complex cx(npts)
|
|
complex cy(npts)
|
|
real a(5),deltaa(5)
|
|
|
|
a(1)=0.
|
|
a(2)=0.
|
|
a(3)=0.
|
|
a(4)=45.0*(ipol-1.0)
|
|
|
|
deltaa(1)=2.0
|
|
deltaa(2)=2.0
|
|
deltaa(3)=2.0
|
|
deltaa(4)=22.5
|
|
deltaa(5)=0.05
|
|
nterms=4
|
|
|
|
chisqr=0.
|
|
nfree=npts-nterms
|
|
|
|
C Start the iteration
|
|
chisqr0=1.e6
|
|
do iter=1,3 !One iteration is enough?
|
|
do j=1,nterms
|
|
chisq1=fchisq(cx,cy,npts,fsample,nflip,a,ccfmax,dtmax)
|
|
fn=0.
|
|
delta=deltaa(j)
|
|
10 a(j)=a(j)+delta
|
|
chisq2=fchisq(cx,cy,npts,fsample,nflip,a,ccfmax,dtmax)
|
|
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(cx,cy,npts,fsample,nflip,a,ccfmax,dtmax)
|
|
if(chisq3.lt.chisq2) then
|
|
chisq1=chisq2
|
|
chisq2=chisq3
|
|
go to 20
|
|
endif
|
|
|
|
C 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.
|
|
enddo
|
|
chisqr=fchisq(cx,cy,npts,fsample,nflip,a,ccfmax,dtmax)
|
|
if(chisqr/chisqr0.gt.0.9999) go to 30
|
|
chisqr0=chisqr
|
|
enddo
|
|
|
|
30 ccfbest=ccfmax * (1378.125/fsample)**2
|
|
dtbest=dtmax
|
|
|
|
if(a(4).lt.0.0) a(4)=a(4)+180.0
|
|
if(a(4).ge.180.0) a(4)=a(4)-180.0
|
|
if(nint(a(4)).eq.180) a(4)=0.
|
|
ipol=nint(a(4)/45.0) + 1
|
|
if(ipol.gt.4) ipol=ipol-4
|
|
|
|
return
|
|
end
|