docs: def main():
      """
      NAME
          bootams.py
  
      DESCRIPTION
        calculates bootstrap statistics for tensor data
  
      SYNTAX
          bootams.py [-h][command line options]
  
      OPTIONS:
          -h prints help message and quits
          -f FILE specifies input file name
          -par specifies parametric bootstrap [by whole data set]
          -n N  specifies the number of bootstrap samples, default is N=1000
  
      INPUT
           x11 x22 x33 x12 x23 x13
  
      OUTPUT
       tau_1 tau_1_sigma V1_dec V1_inc V1_eta V1_eta_dec V1_eta_inc V1_zeta V1_zeta_dec V1_zeta_inc
       tau_2 tau_2_sigma V2_dec V2_inc V2_eta V2_eta_dec V2_eta_inc V2_zeta V2_zeta_dec V2_zeta_inc
       tau_3 tau_2_sigma V3_dec V3_inc V3_eta V3_eta_dec V3_eta_inc V3_zeta V3_zeta_dec V3_zeta_inc
      """
  # set options
      ipar,nb=0,5000
      if '-h' in sys.argv:
          print(main.__doc__)
          sys.exit()
      if '-f' in sys.argv:
          ind=sys.argv.index('-f')
          file=sys.argv[ind+1]
          Ss=np.loadtxt(file)
          #f=open(file,'r')
          #data=f.readlines()
      if '-par' in sys.argv:ipar=1
      if '-n' in sys.argv:
          ind=sys.argv.index('-n')
          nb=int(sys.argv[ind+1])
  # read in the data
      print("Doing bootstrap - be patient")
      #Ss=[]
      #for line in data:
      #    s=[]
      #    rec=line.split()
      #    for i in range(6):
      #        s.append(float(rec[i]))
      #    Ss.append(s)
      Tmean,Vmean,Taus,Vs=pmag.s_boot(Ss,ipar=ipar,nb=nb)
      bpars=pmag.sbootpars(Taus,Vs) # calculate kent parameters for bootstrap
      bpars["v1_dec"]=Vmean[0][0]
      bpars["v1_inc"]=Vmean[0][1]
      bpars["v2_dec"]=Vmean[1][0]
      bpars["v2_inc"]=Vmean[1][1]
      bpars["v3_dec"]=Vmean[2][0]
      bpars["v3_inc"]=Vmean[2][1]
      bpars["t1"]=Tmean[0]
      bpars["t2"]=Tmean[1]
      bpars["t3"]=Tmean[2]
      print("""
  tau tau_sigma V_dec V_inc V_eta V_eta_dec V_eta_inc V_zeta V_zeta_dec V_zeta_inc
  """)
      outstring='%7.5f %7.5f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f'%(bpars["t1"],bpars["t1_sigma"],bpars["v1_dec"],bpars["v1_inc"],bpars["v1_zeta"],bpars["v1_zeta_dec"],bpars["v1_zeta_inc"],bpars["v1_eta"],bpars["v1_eta_dec"],bpars["v1_eta_inc"])
      print(outstring)
      outstring='%7.5f %7.5f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f'%(bpars["t2"],bpars["t2_sigma"],bpars["v2_dec"],bpars["v2_inc"],bpars["v2_zeta"],bpars["v2_zeta_dec"],bpars["v2_zeta_inc"],bpars["v2_eta"],bpars["v2_eta_dec"],bpars["v2_eta_inc"])
      print(outstring)
      outstring='%7.5f %7.5f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f %7.1f'%(bpars["t3"],bpars["t3_sigma"],bpars["v3_dec"],bpars["v3_inc"],bpars["v3_zeta"],bpars["v3_zeta_dec"],bpars["v3_zeta_inc"],bpars["v3_eta"],bpars["v3_eta_dec"],bpars["v3_eta_inc"])
      print(outstring)