anchor.diff:      real, intent(in) :: mv              ! Missing value
       ! - local
       integer :: it, igap
  -    
  -    
  +
  +
       ! Read
       open(11,file=trim(fname),form='unformatted',status='old')
       do it = 1, nt
  
positive.code:     integer :: it, igap
      real :: zx(ns),zn
      logical :: bad(ns)
      
      ! Write
      zn = 0.
      open(11,file=trim(fname),form='unformatted')
      do it = 1, nt
          zx = x(:, it)
          bad = zx==mv
          where(bad)zx = 1./(zn*2)
          if(all(bad))then
              igap = 0
          elseif(any(bad))then
  
negative.code:         write(11) t(it), igap, zx
      end do
      close(11)
  
  end subroutine write_anaxv_field
  
  
  subroutine read_anaxv_field(fname, t, x, ns, nt, mv)
      ! t,x = read_anaxv_field(fname,ns,nt,mv)
  
      implicit none
  
      ! Declarations
      ! - external
      integer, intent(in) ::  ns, &       ! Spatial (channel) dim
  