def float_list_string(vals, nchar=7, ndec=3, nspaces=2, mesg='', left=False):

   """return a string to display the floats:
        vals    : the list of float values
        nchar   : [7] number of characters to display per float
        ndec    : [3] number of decimal places to print to
        nspaces : [2] number of spaces between each float
   """

   if left:
      format = '%-*.*f%*s'
   else:
      format = '%*.*f%*s'

   istr = mesg
   for val in vals:
      istr += format % (nchar, ndec, val, nspaces, '')

   return istr