@_log<EOL><INDENT>def filter_threshold(self, analyte, threshold):<DEDENT>
params = locals()<EOL>del(params['<STR_LIT>'])<EOL>below, above = filters.threshold(self.focus[analyte], threshold)<EOL>setn = self.filt.maxset + <NUM_LIT:1><EOL>self.filt.add(analyte + '<STR_LIT>',<EOL>below,<EOL>'<STR_LIT>'.format(threshold) + analyte,<EOL>params, setn=setn)<EOL>self.filt.add(analyte + '<STR_LIT>',<EOL>above,<EOL>'<STR_LIT>'.format(threshold) + analyte,<EOL>params, setn=setn)<EOL>
Apply threshold filter.

Generates threshold filters for the given analytes above and below
the specified threshold.

Two filters are created with prefixes '_above' and '_below'.
    '_above' keeps all the data above the threshold.
    '_below' keeps all the data below the threshold.

i.e. to select data below the threshold value, you should turn the
'_above' filter off.

Parameters
----------
analyte : TYPE
    Description of `analyte`.
threshold : TYPE
    Description of `threshold`.

Returns
-------
None