Usage: averages [-h|--help] [-version] [-newtags] [-strict] \ 
                   [-novar] [-stddev] [-tag nomvar] \ 
                   [-npas0] [-dateo] \ 
                   [-mean mean_out] [-var var_out] \ 
                   [-weight ip3|time|hours|days|nnn] \ 
                   [-ens] [-etiket] [-status path/to/status/file] \ 
                   [-test] [-q[q]] [-v[v][v]] [--|-f] \ 
                   [mean_out] [var_out] in_1 ... in_n
 
 
  Author: M.Valin, UQAM Centre ESCER.
  Latest revision: $Header: Retouche-a-la-documentation-de-AVERAGES @ 2019-05-20 16:15:18 -0400 (dugas) $
 
 
  This program calculates time averages and variances of sets of CMC/RPN
  files. It can alternatively calculate ensemble means and variances of
  a set of files that all have the same internal structure, which is the
  case, for example, with an output of an ensemble prediction system.
 
 
   Notes: 1) File var_out MUST NOT be present if the '-novar' or '-var'
             arguments are specified. As well, if the '-mean' argument
             is specified, file mean_out MUST NOT be present
          2) The '-var' and '-novar' arguments are mutually
             exclusive and may not be used together
          3) Options are order independent *** BUT *** one
             or the other of '--' and '-f' MUST BE THE LAST ONE.
             And the list of input files has to follow this.
          4) Default special tag names = '>>  ', '^^  ', '!!  ', 'HY  '"
             The -tag option may be used more than once to add to this list.
             These are special records that are only copied to the output
             file(s) when seen the first time and skipped afterwards
          5) The internal etiket is ignored except if '-etiket'
             argument is specified on the command line'
          6) The '-ens' argument activates the ensemble mode, where
             averages/stds are calculated across files. All such
             files should then have an identical structure
          7) The '-v', '-vv' and '-vvv' arguments toggle the INFO,
             NOTE and DEBUG message modes, respectively, while the
             '-q' and '-qq' arguments respectively toggle the
             'ERROR messages only' and 'NO messages at all' modes
 
   Example :'
           averages -status stat.dot -vv -mean mean.fst -var var.fst \ 
                    -tag HY -tag '>>' my_dir/dm*
 
 
   Error exits
    1 Option is too long
    2 Missing value after argument -weight
    3 Missing value after argument -mean
    4 Missing value after argument -status
    5 Missing value after argument -tag
    6 Arguments -var and -novar are mutually exclusive
    7 Missing value after argument -var
    8 Unrecognized option         (only in strict mode)
    9 Cannot allocate page table
   10 Mean output file exists     (only in strict mode)
   11 Variance output file exists (only in strict mode)
   12 Input file not found        (only in strict mode)
   13 Error while processing file
   14 Missing sample(s) for some variables (only in strict mode)