Initial Commit

lib/inter_wspr.f90

@@ -0,0 +1,45 @@
+subroutine inter_wspr(id,ndir)
+
+! Interleave (ndir=1) or de-interleave (ndir=-1) the array id.
+
+  integer*1 id(0:161),itmp(0:161)
+  integer j0(0:161)
+  logical first
+  data first/.true./
+  save
+
+  if(first) then
+! Compute the interleave table using bit reversal.
+     k=-1
+     do i=0,255
+        n=0
+        ii=i
+        do j=0,7
+           n=n+n
+           if(iand(ii,1).ne.0) n=n+1
+           ii=ii/2
+        enddo
+        if(n.le.161) then
+           k=k+1
+           j0(k)=n
+        endif
+     enddo
+     first=.false.
+  endif
+
+  if(ndir.eq.1) then
+     do i=0,161
+        itmp(j0(i))=id(i)
+     enddo
+  else
+     do i=0,161
+        itmp(i)=id(j0(i))
+     enddo
+  endif
+
+  do i=0,161
+     id(i)=itmp(i)
+  enddo
+
+  return
+end subroutine inter_wspr