From e7889ba11bf17d407089959cf346fd058b9bf30b Mon Sep 17 00:00:00 2001
From: Steve Franke <s.j.franke@icloud.com>
Date: Mon, 24 Jun 2019 11:09:55 -0500
Subject: [PATCH] FT4: candidates within 20 Hz of nfqso are presented to the
 decoder first.

---
 lib/ft4/getcandidates4.f90 | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/lib/ft4/getcandidates4.f90 b/lib/ft4/getcandidates4.f90
index 09c2f135d..e9860b7a7 100644
--- a/lib/ft4/getcandidates4.f90
+++ b/lib/ft4/getcandidates4.f90
@@ -8,7 +8,7 @@ subroutine getcandidates4(dd,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
   real x(NFFT1)
   real window(NFFT1)
   complex cx(0:NH1)
-  real candidate(2,maxcand)
+  real candidate(2,maxcand),candidatet(2,maxcand)
   real dd(NMAX)
   integer ipk(1)
   equivalence (x,cx)
@@ -48,11 +48,12 @@ subroutine getcandidates4(dd,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
   if(nfa.lt.nint(200.0/df)) nfa=nint(200.0/df)
   nfb=fb/df
   if(nfb.gt.nint(4910.0/df)) nfb=nint(4910.0/df)
-  ncand=0
   call ft4_baseline(savg,nfa,nfb,sbase)
   if(any(sbase(nfa:nfb).le.0)) return 
   savsm(nfa:nfb)=savsm(nfa:nfb)/sbase(nfa:nfb)
   f_offset = -1.5*12000.0/NSPS
+  ncand=0
+  candidatet=0
   do i=nfa+1,nfb-1
      if(savsm(i).ge.savsm(i-1) .and. savsm(i).ge.savsm(i+1) .and.      &
           savsm(i).ge.syncmin) then
@@ -63,11 +64,23 @@ subroutine getcandidates4(dd,fa,fb,syncmin,nfqso,maxcand,savg,candidate,   &
         if(fpeak.lt.200.0 .or. fpeak.gt.4910.0) cycle
         speak=savsm(i) - 0.25*(savsm(i-1)-savsm(i+1))*del
         ncand=ncand+1
-        candidate(1,ncand)=fpeak
-        candidate(2,ncand)=speak
+        candidatet(1,ncand)=fpeak
+        candidatet(2,ncand)=speak
         if(ncand.eq.maxcand) exit
      endif
   enddo
-
+  candidate=0
+  nq=count(abs(candidatet(1,1:ncand)-nfqso).le.20.0)
+  n1=1
+  n2=nq+1 
+  do i=1,ncand
+     if(abs(candidatet(1,i)-nfqso).le.20.0) then
+        candidate(1:2,n1)=candidatet(1:2,i)
+        n1=n1+1
+     else
+        candidate(1:2,n2)=candidatet(1:2,i)
+        n2=n2+1
+     endif
+  enddo 
 return
 end subroutine getcandidates4