anchor.diff:  c     Start period search     *
   c******************************
   c
  -      do 100 jf=1,nf
  +      do 100 jf=1,nfreqs
   c
            f0=fmin+df*dfloat(jf-1)
            p0=1.0d0/f0
  
positive.code: c     -- Dimensions of arrays {y(i)} and {ibi(i)} MUST be greater than
  c     or equal to  *nbinsmax*.
  c     -- The lowest number of points allowed in a single bin is equal
  c     to   MAX(minbin,qmin*N),  where   *qmin*  is the minimum transit
  c     length/trial period,   *N*  is the total number of data points,
  c     *minbin*  is the preset minimum number of the data points per
  c     bin.
  c
  c========================================================================
  
negative.code: c     u    = temporal/work/dummy array, must be dimensioned in the
  c     calling program in the same way as  {t(i)}
  c     v    = the same as  {u(i)}
  c     nfreqs   = number of frequency points in which the spectrum is computed
  c     fmin = minimum frequency (MUST be > 0)
  c     df   = frequency step
  c     nbins   = number of bins in the folded time series at any test period
  