Expose mean hwlw for spring/neap tide (#175)

* exposed mean ext for springneap

* added test

* updated whatsnew

docs/whats-new.md

@@ -9,6 +9,7 @@
 - support for timedelta `diff()` because of update to `pandas>=2.1.4` in #161
 - neater handling of time in `kw.calc_havengetallen()` in #163
 - automatic cropping of timeseries if required to simplify user interaction in #168
+- exposed mean HW/LW during spring and neaptide with `kw.calc_HWLW_springneap()` in #175
 
 ### Deprecated
 - deprecated debug argument for `kw.calc_gemiddeldgetij()` in #170

examples/KWK_process.py

@@ -100,6 +100,7 @@
         # compute and plot tidal indicators
         dict_wltidalindicators = kw.calc_wltidalindicators(df_meas=df_meas_todate, min_coverage=min_coverage)
         dict_HWLWtidalindicators = kw.calc_HWLWtidalindicators(df_ext=df_ext_todate, min_coverage=min_coverage)
+        dict_HWLW_springneap = kw.calc_HWLW_springneap(df_ext=df_ext_todate, min_coverage=min_coverage)
 
         # add hat/lat
         hat, lat = kw.calc_hat_lat_frommeasurements(df_meas_todate)
@@ -108,6 +109,7 @@
 
         # merge dictionaries
         dict_wltidalindicators.update(dict_HWLWtidalindicators)
+        dict_wltidalindicators.update(dict_HWLW_springneap)
 
         # csv for yearlymonthly indicators
         for key in ['wl_mean_peryear','wl_mean_permonth']:

kenmerkendewaarden/havengetallen.py

@@ -24,6 +24,7 @@
 
 __all__ = [
     "calc_havengetallen",
+    "calc_HWLW_springneap",
     "plot_HWLW_pertimeclass",
     "plot_aardappelgrafiek",
 ]
@@ -73,30 +74,10 @@ def calc_havengetallen(
     raise_extremes_with_aggers(df_ext)
     df_ext_10y = crop_timeseries_last_nyears(df=df_ext, nyears=10)
 
-    # check if coverage is high enough for havengetallen
+    # check if coverage is high enough
     if min_coverage is not None:
-        # TODO: compute_actual_counts only returns years for which there are no nans, so will have different length than expected counts if there is an all-nan year
-        # TODO: if we supply 4 years of complete data instead of 10 years, no error is raised
-        data_pd_hw = df_ext_10y.loc[df_ext_10y["HWLWcode"] == 1]["values"]
-        df_actual_counts_peryear = compute_actual_counts(data_pd_hw, freq="Y")
-        df_expected_counts_peryear = compute_expected_counts(data_pd_hw, freq="Y")
-        # floor expected counts to avoid rounding issues
-        df_expected_counts_peryear = df_expected_counts_peryear.apply(np.floor)
-        df_min_counts_peryear = df_expected_counts_peryear * min_coverage
-        bool_coverage_toolow = df_actual_counts_peryear < df_min_counts_peryear
-        df_debug = pd.DataFrame(
-            {
-                "#required": df_min_counts_peryear,
-                "#actual": df_actual_counts_peryear,
-                "too little": bool_coverage_toolow,
-            }
-        )
-        if bool_coverage_toolow.any():
-            raise ValueError(
-                f"coverage of some years is lower than "
-                f"min_coverage={min_coverage}:\n{df_debug}"
-            )
-
+        check_min_coverage_extremes(df_ext=df_ext_10y, min_coverage=min_coverage)
+
     current_station = df_ext_10y.attrs["station"]
     logger.info(f"computing havengetallen for {current_station}")
     df_ext_culm = calc_hwlw_moonculm_combi(df_ext=df_ext_10y, moonculm_offset=moonculm_offset)
@@ -106,6 +87,79 @@ def calc_havengetallen(
         return df_havengetallen, df_ext_culm
     else:
         return df_havengetallen
+
+
+def calc_HWLW_springneap(
+        df_ext: pd.DataFrame,
+        min_coverage=None,
+        moonculm_offset: int = 4):
+    raise_extremes_with_aggers(df_ext)
+
+    # TODO: moonculminations cannot be computed before 1900
+    if df_ext.index.min().year < 1901:
+        logger.warning("calc_HWLW_springneap() only supports timestamps after 1900 "
+                       "all older data will be ignored")
+        df_ext = df_ext.loc["1901":]
+
+    # check if coverage is high enough
+    if min_coverage is not None:
+        check_min_coverage_extremes(df_ext=df_ext, min_coverage=min_coverage)
+
+    current_station = df_ext.attrs["station"]
+    logger.info(f"computing HWLW for spring/neap tide for {current_station}")
+    df_ext_culm = calc_hwlw_moonculm_combi(df_ext=df_ext, moonculm_offset=moonculm_offset)
+
+    # all HW/LW at spring/neaptide
+    bool_hw = df_ext_culm["HWLWcode"] == 1
+    bool_lw = df_ext_culm["HWLWcode"] == 2
+    bool_spring = df_ext_culm["culm_hr"] == 0
+    bool_neap = df_ext_culm["culm_hr"] == 6
+    hw_spring = df_ext_culm.loc[bool_hw & bool_spring]['values']
+    lw_spring = df_ext_culm.loc[bool_lw & bool_spring]['values']
+    hw_neap = df_ext_culm.loc[bool_hw & bool_neap]['values']
+    lw_neap = df_ext_culm.loc[bool_lw & bool_neap]['values']
+
+    # mean HW/LW at spring/neap tide
+    pi_hw_sp_y = pd.PeriodIndex(hw_spring.index, freq="Y")
+    pi_lw_sp_y = pd.PeriodIndex(lw_spring.index, freq="Y")
+    pi_hw_np_y = pd.PeriodIndex(hw_neap.index, freq="Y")
+    pi_lw_np_y = pd.PeriodIndex(lw_neap.index, freq="Y")
+    hw_spring_peryear = hw_spring.groupby(pi_hw_sp_y).mean()
+    lw_spring_peryear = lw_spring.groupby(pi_lw_sp_y).mean()
+    hw_neap_peryear = hw_neap.groupby(pi_hw_np_y).mean()
+    lw_neap_peryear = lw_neap.groupby(pi_lw_np_y).mean()
+
+    # merge in dict
+    dict_hwlw_springneap = {
+        "HW_spring_mean_peryear": hw_spring_peryear,
+        "LW_spring_mean_peryear": lw_spring_peryear,
+        "HW_neap_mean_peryear": hw_neap_peryear,
+        "LW_neap_mean_peryear": lw_neap_peryear,
+    }
+    return dict_hwlw_springneap
+
+
+def check_min_coverage_extremes(df_ext, min_coverage):
+    # TODO: compute_actual_counts only returns years for which there are no nans, so will have different length than expected counts if there is an all-nan year
+    # TODO: if we supply 4 years of complete data instead of 10 years, no error is raised
+    data_pd_hw = df_ext.loc[df_ext["HWLWcode"] == 1]["values"]
+    df_actual_counts_peryear = compute_actual_counts(data_pd_hw, freq="Y")
+    df_expected_counts_peryear = compute_expected_counts(data_pd_hw, freq="Y")
+    # floor expected counts to avoid rounding issues
+    df_expected_counts_peryear = df_expected_counts_peryear.apply(np.floor)
+    df_min_counts_peryear = df_expected_counts_peryear * min_coverage
+    bool_coverage_toolow = df_actual_counts_peryear < df_min_counts_peryear
+    df_debug = pd.DataFrame(
+        {
+            "#required": df_min_counts_peryear.loc[bool_coverage_toolow],
+            "#actual": df_actual_counts_peryear.loc[bool_coverage_toolow],
+        }
+    )
+    if bool_coverage_toolow.any():
+        raise ValueError(
+            f"coverage of some years is lower than "
+            f"min_coverage={min_coverage}:\n{df_debug}"
+        )
 
 
 def get_moonculm_idxHWLWno(tstart, tstop):

tests/test_havengetallen.py

@@ -152,6 +152,35 @@ def test_calc_havengetallen_toolittle_data(df_ext_12_2010_2014):
     assert "coverage of some years is lower than min_coverage" in str(e.value)
 
 
+@pytest.mark.unittest
+def test_calc_HWLW_springneap(df_ext_12_2010_2014):
+    dict_spnp = kw.calc_HWLW_springneap(df_ext_12_2010_2014)
+    df_columns = ['HW_spring_mean_peryear', 'LW_spring_mean_peryear', 
+                  'HW_neap_mean_peryear', 'LW_neap_mean_peryear']
+    assert set(dict_spnp.keys()) == set(df_columns)
+
+    for key in df_columns:
+        years_act = dict_spnp[key].index.year.tolist()
+        years_exp = [2010, 2011, 2012, 2013, 2014]
+        assert years_act == years_exp
+
+    vals_act = dict_spnp['HW_spring_mean_peryear'].values
+    vals_exp = np.array([1.33551724, 1.28111111, 1.29563636, 1.33185185, 1.37745455])
+    assert np.allclose(vals_act, vals_exp)
+
+    vals_act = dict_spnp['LW_spring_mean_peryear'].values
+    vals_exp = np.array([-0.59724138, -0.6212963, -0.61872727, -0.60407407, -0.60145455])
+    assert np.allclose(vals_act, vals_exp)
+
+    vals_act = dict_spnp['HW_neap_mean_peryear'].values
+    vals_exp = np.array([0.83887097, 0.95854839, 0.86225806, 0.87903226, 0.9696875])
+    assert np.allclose(vals_act, vals_exp)
+
+    vals_act = dict_spnp['LW_neap_mean_peryear'].values
+    vals_exp = np.array([-0.62919355, -0.46758065, -0.5633871 , -0.60193548, -0.51421875])
+    assert np.allclose(vals_act, vals_exp)
+
+
 @pytest.mark.unittest
 def test_calc_HWLW_culmhr_summary_tidalcoeff(df_ext_12_2010):
     """