`flagByStatLowPass` is overwriting existing flags

CHANGELOG.md

@@ -21,6 +21,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
 - `func` arguments in text configurations were not parsed correctly
 - fail on duplicated arguments to test methods
 - `reample` was not writing meta entries
+- `flagByStatLowPass` was overwriting existing flags
 
 ## [2.3.0](https://git.ufz.de/rdm-software/saqc/-/tags/v2.3.0) - 2023-01-17
 [List of commits](https://git.ufz.de/rdm-software/saqc/-/compare/v2.2.1...v2.3.0)

saqc/funcs/noise.py

@@ -13,9 +13,9 @@ from typing import TYPE_CHECKING, Callable
 import numpy as np
 import pandas as pd
 
-from saqc import BAD
-from saqc.core import flagging
-from saqc.lib.tools import statPass
+from saqc.constants import BAD
+from saqc.core.register import flagging
+from saqc.lib.tools import isflagged, statPass
 
 if TYPE_CHECKING:
     from saqc import SaQC
@@ -95,5 +95,6 @@ class NoiseMixin:
             sub_thresh,
             min_periods,
         )
-        self._flags[to_set, field] = flag
+        mask = ~isflagged(self._flags[field], kwargs["dfilter"]) & to_set
+        self._flags[mask, field] = flag
         return self