WSJT-X/lib/peakdf9.f90

subroutine peakdf9(c0,npts8,nsps8,istart,foffset,idfpk)

  complex c0(0:npts8-1)
  complex zsum
  integer ii(16)                       !Locations of sync symbols
  data ii/1,6,11,16,21,26,31,39,45,51,57,63,69,75,81,85/

  twopi=8.0*atan(1.0)
  df=1500.0/nsps8
  smax=0.
  do idf=-5,5
     f0=foffset + 0.1*df*idf
     dphi=twopi*f0/1500.0
     sum=0.
     do j=1,16
        i1=(ii(j)-1)*nsps8 + istart
        phi=0.
        zsum=0.
        do i=i1,i1+nsps8-1
           if(i.lt.0 .or. i.gt.npts8-1) cycle
           phi=phi + dphi
           zsum=zsum + c0(i) * cmplx(cos(phi),-sin(phi))
        enddo
        sum=sum + real(zsum)**2 + aimag(zsum)**2
     enddo
     if(sum.gt.smax) then
        idfpk=idf
        smax=sum
     endif
  enddo

  return
end subroutine peakdf9
Can decode in modes 1 2 5 10, but not 30 -- why??? git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2643 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 2012-10-03 14:39:37 -04:00			`subroutine peakdf9(c0,npts8,nsps8,istart,foffset,idfpk)`
Working on peakups for DF and DT. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2642 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 2012-10-03 13:47:55 -04:00
			`complex c0(0:npts8-1)`
			`complex zsum`
			`integer ii(16) !Locations of sync symbols`
			`data ii/1,6,11,16,21,26,31,39,45,51,57,63,69,75,81,85/`

			`twopi=8.0*atan(1.0)`
			`df=1500.0/nsps8`
			`smax=0.`
Can decode in modes 1 2 5 10, but not 30 -- why??? git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2643 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 2012-10-03 14:39:37 -04:00			`do idf=-5,5`
Working on peakups for DF and DT. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2642 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 2012-10-03 13:47:55 -04:00			`f0=foffset + 0.1dfidf`
			`dphi=twopi*f0/1500.0`
			`sum=0.`
			`do j=1,16`
			`i1=(ii(j)-1)*nsps8 + istart`
			`phi=0.`
			`zsum=0.`
			`do i=i1,i1+nsps8-1`
Can decode in modes 1 2 5 10, but not 30 -- why??? git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2643 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 2012-10-03 14:39:37 -04:00			`if(i.lt.0 .or. i.gt.npts8-1) cycle`
Working on peakups for DF and DT. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2642 ab8295b8-cf94-4d9e-aec4-7959e3be5d79 2012-10-03 13:47:55 -04:00			`phi=phi + dphi`
			`zsum=zsum + c0(i) * cmplx(cos(phi),-sin(phi))`
			`enddo`
			`sum=sum + real(zsum)2 + aimag(zsum)2`
			`enddo`
			`if(sum.gt.smax) then`
			`idfpk=idf`
			`smax=sum`
			`endif`
			`enddo`

			`return`
			`end subroutine peakdf9`