anchor.diff:    wid = -1
     uprm = 0
     urst = 0
  -  useq = 0
  -  mc_nsweeps = 0
  -  nupdate = 10
  -  niter_gd = 0
  -  niter_agd = 0
  -  lambda = 0.01_kflt
     mode = 'EVAL'
     rseed = 0
  -  beta = 1.0_kflt
   
     !================================================ init. unit identifiers
   
  
positive.code:      write(ulog,'(a,1x,i8)')   '#  n. of variables              = ', nvars
       write(ulog,'(a,1x,i8)')   '#  n. of classes                = ', nclasses
       write(ulog,'(a,1x,i8)')   '#  n. of seqs                   = ', nseqs
       write(ulog,'(a,1x,i8)')   '#  stride (sweeps) for updates  = ', nupdate
       if (trim(mode) == 'SIM') &
            write(ulog,'(a,1x,i8)')   '#  n. of MC sweeps              = ', mc_nsweeps
       write(ulog,'(a,1x,f8.1)') '#  temperature factor           = ', 1.0_kflt / beta
       if (trim(mode) == 'LEARN') then
          if (wid > 0.0 .or. uwgt > 0.0) then
             if (wid > 0.0) then
                write(ulog,'(a,1x,f8.1)') &
                     '#  %id for reweighting          = ', wid
             else if (uwgt > 0.0) then
                write(ulog,'(a)') &
                     '#  reading weights from file...    '
             end if
             write(ulog,'(a,1x,f8.1)') '#  effective n. of seqs         = ', neff
          end if
          write(ulog,'(a,1x,f8.3)') '#  scaled prior (hyper-)parameter  = ', lambda
          write(ulog,'(a,1x,i8)')   '#  MC sweeps per gradient est.  = ', mc_nsweeps
          write(ulog,'(a,1x,i8)')   '#  n. of iterations (GD)        = ', niter_gd
          write(ulog,'(a,1x,i8)')   '#  n. of iterations (AGD)       = ', niter_agd
       end if
       write(ulog,'(a)')         '#'
       write(ulog,'(a)')         '#==========================================='
       write(ulog,'(a)')         '#'
  
negative.code:   real(kflt)                 :: wid          ! %id for weights calculation
    integer                    :: uprm         ! prm unit
    integer                    :: urst         ! rst unit
    character(len=string_size) :: mode         ! run mode: EVAL, SIM, LEARN
    integer                    :: rseed        ! random seed
    integer                         :: iproc=0,nproc=1
    integer                         :: err
    character(long_string_size)     :: err_string
    integer                         :: dim1,dim2
    integer                         :: uene,ulog
    character(len=long_string_size) :: filename
    integer                         :: j
    real(kflt)                      :: etot,efields,ecouplings
  
    !================================================ set defaults
  
  