def write_polfils(str, str_I, **kwargs):
lin,circ=fracpols(str, **kwargs)<EOL>obs = Waterfall(str_I, max_load=<NUM_LIT>)<EOL>obs.data = lin<EOL>obs.write_to_fil(str[:-<NUM_LIT:15>]+'<STR_LIT>')   <EOL>obs.data = circ<EOL>obs.write_to_fil(str[:-<NUM_LIT:15>]+'<STR_LIT>')<EOL>
Writes two new filterbank files containing fractional linear and
    circular polarization data