docs: def main():
      """
      NAME
         plotxy_magic.py
  
      DESCRIPTION
         Makes simple X,Y plots 
  
      INPUT FORMAT
         Any MagIC formatted file
  
      SYNTAX
         plotxy_magic.py [command line options] 
  
      OPTIONS
          -h prints this help message
          -f FILE to set file name on command rec 
          -c col1 col2 specify columns names to plot
          -sym SYM SIZE specify symbol and size to plot: default is red dots
          -S   don't plot symbols
          -xlab XLAB
          -ylab YLAB
          -l  connect symbols with lines
          -b xmin xmax ymin ymax, sets bounds
  #        -b [key:max:min,key:max:min,etc.] leave or min blank for no cutoff
      """
      col1,col2=0,1
      sym,size = 'ro',20
      xlab,ylab='',''
      lines=0
      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]
      else:
          '-f option is a required field'
          print(main.__doc__)
          sys.exit()
      if '-c' in sys.argv:
          ind=sys.argv.index('-c')
          col1=sys.argv[ind+1]
          col2=sys.argv[ind+2]
      else:
          'Column headers a required field'
          print(main.__doc__)
          sys.exit()
      if '-xlab' in sys.argv:
          ind=sys.argv.index('-xlab')
          xlab=sys.argv[ind+1]
      if '-ylab' in sys.argv:
          ind=sys.argv.index('-ylab')
          ylab=sys.argv[ind+1]
  #    if '-b' in sys.argv:
  #        ind=sys.argv.index('-b')
  #        bounds=sys.argv[ind+1].split(',')
      if '-b' in sys.argv:
          ind=sys.argv.index('-b')
          xmin=float(sys.argv[ind+1])
          xmax=float(sys.argv[ind+2])
          ymin=float(sys.argv[ind+3])
          ymax=float(sys.argv[ind+4])
      if '-sym' in sys.argv:
          ind=sys.argv.index('-sym')
          sym=sys.argv[ind+1]
          size=int(sys.argv[ind+2])
      if '-l' in sys.argv: lines=1
      if '-S' in sys.argv: sym=''
      X,Y=[],[]
      data,file_type=pmag.magic_read(file)
      print(file_type)
      for rec in data:
          if col1 not in list(rec.keys()) or col2 not in list(rec.keys()):
              print(col1,' and/or ',col2, ' not in file headers')
              print('try again')
              sys.exit()
          if rec[col1]!='' and rec[col2]!='':
              skip=0
              if '-crit' in sys.argv:
                  for crit in bounds:
                      crits=crit.split(':')
                      crit_key=crits[0]
                      crit_min=crits[1]
                      crit_max=crits[2]
                      if rec[crit_key]=="":
                          skip=1
                      else:
                          if crit_min!="" and float(rec[crit_key])<float(crit_min):skip=1
                          if crit_max!="" and float(rec[crit_key])>float(crit_min):skip=1
              if skip==0:
                  X.append(float(rec[col1]))
                  Y.append(float(rec[col2]))
      if len(X)==0:
              print(col1,' and/or ',col2, ' have no data ')
              print('try again')
              sys.exit()
      else:
          print(len(X),' data points')
      if sym!='':pylab.scatter(X,Y,c=sym[0],marker=sym[1],s=size)
      if xlab!='':pylab.xlabel(xlab)
      if ylab!='':pylab.ylabel(ylab)
      if lines==1:pylab.plot(X,Y,'k-')
      if '-b' in sys.argv:pylab.axis([xmin,xmax,ymin,ymax])
      pylab.draw()
      ans=input("Press return to quit  ")
      sys.exit()