docs: def main():
      """
      NAME
          aniso_magic.py
  
      DESCRIPTION
          plots anisotropy data with either bootstrap or hext ellipses
  
      SYNTAX
          aniso_magic.py [-h] [command line options]
      OPTIONS
          -h plots help message and quits
          -usr USER: set the user name
          -f AFILE, specify specimens.txt formatted file for input
          -fsa SAMPFILE, specify samples.txt file (required to plot by site)
          -fsi SITEFILE, specify site file (required to include location information)
          -x Hext [1963] and bootstrap
          -B DON'T do bootstrap, do Hext
          -par Tauxe [1998] parametric bootstrap
          -v plot bootstrap eigenvectors instead of ellipses
          -sit plot by site instead of entire file
          -crd [s,g,t] coordinate system, default is specimen (g=geographic, t=tilt corrected)
          -P don't make any plots - just fill in the specimens, samples, sites tables
          -sav don't make the tables - just save all the plots
          -fmt [svg, jpg, eps] format for output images, png default
          -gtc DEC INC  dec,inc of pole to great circle [down(up) in green (cyan)
          -d Vi DEC INC; Vi (1,2,3) to compare to direction DEC INC
          -n N; specifies the number of bootstraps - default is 1000
      DEFAULTS
         AFILE:  specimens.txt
         plot bootstrap ellipses of Constable & Tauxe [1987]
      NOTES
         minor axis: circles
         major axis: triangles
         principal axis: squares
         directions are plotted on the lower hemisphere
         for bootstrapped eigenvector components: Xs: blue, Ys: red, Zs: black
  """
      args = sys.argv
      if "-h" in args:
          print(main.__doc__)
          sys.exit()
      verbose = pmagplotlib.verbose
      dir_path = pmag.get_named_arg("-WD", ".")
      input_dir_path = pmag.get_named_arg("-ID", "")
      num_bootstraps = pmag.get_named_arg("-n", 1000)
      ipar = pmag.get_flag_arg_from_sys("-par", true=1, false=0)
      ihext = pmag.get_flag_arg_from_sys("-x", true=1, false=0)
      ivec = pmag.get_flag_arg_from_sys("-v", true=1, false=0)
      iplot = pmag.get_flag_arg_from_sys("-P", true=0, false=1)
      isite = pmag.get_flag_arg_from_sys("-sit", true=1, false=0)
      iboot, vec = 1, 0
      infile = pmag.get_named_arg('-f', 'specimens.txt')
      samp_file = pmag.get_named_arg('-fsa', 'samples.txt')
      site_file = pmag.get_named_arg('-fsi', 'sites.txt')
      #outfile = pmag.get_named_arg("-F", "rmag_results.txt")
      fmt = pmag.get_named_arg("-fmt", "png")
      crd = pmag.get_named_arg("-crd", "s")
      comp, Dir, PDir = 0, [], []
      user = pmag.get_named_arg("-usr", "")
      if '-B' in args:
          iboot, ihext = 0, 1
      plots, verbose = 0, True
      if '-sav' in args:
          plots = 1
          verbose = 0
      if '-gtc' in args:
          ind = args.index('-gtc')
          d, i = float(args[ind+1]), float(args[ind+2])
          PDir.append(d)
          PDir.append(i)
      if '-d' in args:
          comp = 1
          ind = args.index('-d')
          vec = int(args[ind+1])-1
          Dir = [float(args[ind+2]), float(args[ind+3])]
  
      ipmag.aniso_magic(infile=infile, samp_file=samp_file, site_file=site_file,
                        ipar=ipar, ihext=ihext, ivec=ivec, iplot=iplot, isite=isite, iboot=iboot, vec=vec,
                        Dir=Dir, PDir=PDir, comp=comp, user=user,
                        fmt=fmt, crd=crd, verbose=verbose, plots=plots,
                        num_bootstraps=num_bootstraps, dir_path=dir_path,
                        input_dir_path=input_dir_path)