'Transform raw data.'

def _transform_raw(self, raw, start, stop, reject_by_annotation=False):

    if (not hasattr(self, 'mixing_matrix_')):
        raise RuntimeError('No    fit    available.    Please    fit    ICA.')
    (start, stop) = _check_start_stop(raw, start, stop)
    picks = pick_types(raw.info, include=self.ch_names, exclude='bads', meg=False, ref_meg=False)
    if (len(picks) != len(self.ch_names)):
        raise RuntimeError(("Raw    doesn't    match    fitted    data:    %i    channels    fitted    but    %i    channels    supplied.    \nPlease    provide    Raw    compatible    with    ica.ch_names" % (len(self.ch_names), len(picks))))
    if reject_by_annotation:
        data = raw.get_data(picks, start, stop, 'omit')
    else:
        data = raw[picks, start:stop][0]
    (data, _) = self._pre_whiten(data, raw.info, picks)
    return self._transform(data)
