Revert extra arguments added to handle zero humidity in thermo computations (#26)

* Revert extra arguments added to handle zero humidity in thermo computations

Author: sandorkertesz

docs/release_notes/index.rst

@@ -4,5 +4,6 @@ Release notes
 .. toctree::
     :maxdepth: 1
 
+    version_0.3_updates
     version_0.2_updates
     version_0.1_updates

docs/release_notes/version_0.3_updates.rst

@@ -0,0 +1,14 @@
+Version 0.3 Updates
+/////////////////////////
+
+
+Version 0.3.0
+===============
+
+- Removed the ``eps`` and ``out`` keywords arguments to control zero humidity in
+
+  - :py:meth:`dewpoint_from_specific_humidity <meteo.thermo.array.dewpoint_from_specific_humidity>`
+  - :py:meth:`dewpoint_from_relative_humidity <meteo.thermo.array.dewpoint_from_relative_humidity>`
+  - :py:meth:`temperature_from_saturation_vapour_pressure <meteo.thermo.array.temperature_from_saturation_vapour_pressure>`
+
+  This was done to revert the changes added in version 0.2.0.

src/earthkit/meteo/thermo/array/thermo.py

@@ -263,21 +263,9 @@ def compute_slope(self, t, phase):
         elif phase == "ice":
             return self._es_ice_slope(t)
 
-    def t_from_es(self, es, eps=1e-8, out=None):
-        def _comp(x):
-            x = x / self.c1
-            x = np.log(x)
-            return (x * self.c4w - self.c3w * self.t0) / (x - self.c3w)
-
-        if out is not None:
-            v = np.asarray(es)
-            z_mask = v < eps
-            v_mask = ~z_mask
-            v[v_mask] = _comp(v[v_mask])
-            v[z_mask] = out
-            return v
-        else:
-            return _comp(es)
+    def t_from_es(self, es):
+        v = np.log(es / self.c1)
+        return (v * self.c4w - self.c3w * self.t0) / (v - self.c3w)
 
     def _es_water(self, t):
         return self.c1 * np.exp(self.c3w * (t - self.t0) / (t - self.c4w))
@@ -572,35 +560,26 @@ def saturation_specific_humidity_slope(t, p, es=None, es_slope=None, phase="mixe
     return constants.epsilon * es_slope * p / v
 
 
-def temperature_from_saturation_vapour_pressure(es, eps=1e-8, out=None):
+def temperature_from_saturation_vapour_pressure(es):
     r"""Compute the temperature from saturation vapour pressure.
 
     Parameters
     ----------
     es: ndarray
         :func:`saturation_vapour_pressure` (Pa)
-    eps: number
-        If ``out`` is not None, return ``out`` when ``es`` < ``eps``. If out
-        is None, ``eps`` is ignored and return np.nan for ``es`` values very
-        close to zero. *New in version 0.2.0*
-    out: number or None
-        If not None, return ``out`` when ``es`` < ``eps``. If None, ``eps`` is
-        ignored and return np.nan for ``es`` values very close to zero.
-        *New in version 0.2.0*
-
 
     Returns
     -------
     ndarray
-        Temperature (K)
+        Temperature (K). For zero ``es`` values returns np.nan.
 
 
     The computation is always based on the "water" phase of
     the :func:`saturation_vapour_pressure` formulation irrespective of the
     phase ``es`` was computed to.
 
     """
-    return _EsComp().t_from_es(es, eps=eps, out=out)
+    return _EsComp().t_from_es(es)
 
 
 def relative_humidity_from_dewpoint(t, td):
@@ -775,7 +754,7 @@ def specific_humidity_from_relative_humidity(t, r, p):
     return specific_humidity_from_vapour_pressure(e, p)
 
 
-def dewpoint_from_relative_humidity(t, r, eps=1e-8, out=None):
+def dewpoint_from_relative_humidity(t, r):
     r"""Compute the dewpoint temperature from relative humidity.
 
     Parameters
@@ -784,19 +763,11 @@ def dewpoint_from_relative_humidity(t, r, eps=1e-8, out=None):
         Temperature (K)
     r: ndarray
         Relative humidity (%)
-    eps: number
-        If ``out`` is not None, return ``out`` when ``r`` < ``eps``.
-        If out is None, ``eps`` is ignored and return np.nan for ``r``
-        values very close to zero. *New in version 0.2.0*
-    out: number or None
-        If not None, return ``out`` when ``r`` < ``eps``. If None, ``eps`` is
-        ignored and return np.nan for ``r`` values very close to zero.
-        *New in version 0.2.0*
 
     Returns
     -------
     ndarray
-        Dewpoint temperature (K)
+        Dewpoint temperature (K). For zero ``r`` values returns np.nan.
 
 
     The computation starts with determining the the saturation vapour pressure over
@@ -815,24 +786,11 @@ def dewpoint_from_relative_humidity(t, r, eps=1e-8, out=None):
     equations used in :func:`saturation_vapour_pressure`.
 
     """
-    # by masking upfront we avoid RuntimeWarning when calling log() in
-    # the computation of td when r is very small
-    if out is not None:
-        r = np.asarray(r)
-        mask = r < eps
-        r[mask] = np.nan
-
     es = saturation_vapour_pressure(t, phase="water") * r / 100.0
-    td = temperature_from_saturation_vapour_pressure(es)
+    return temperature_from_saturation_vapour_pressure(es)
 
-    if out is not None and not np.isnan(out):
-        td = np.asarray(td)
-        td[mask] = out
 
-    return td
-
-
-def dewpoint_from_specific_humidity(q, p, eps=1e-8, out=None):
+def dewpoint_from_specific_humidity(q, p):
     r"""Compute the dewpoint temperature from specific humidity.
 
     Parameters
@@ -841,19 +799,11 @@ def dewpoint_from_specific_humidity(q, p, eps=1e-8, out=None):
         Specific humidity (kg/kg)
     p: ndarray
         Pressure (Pa)
-    eps: number
-        If ``out`` is not None, return ``out`` when ``q`` < ``eps``.
-        If out is None, ``eps`` is ignored and return np.nan for ``q``
-        values very close to zero. *New in version 0.2.0*
-    out: number or None
-        If not None, return ``out`` when ``q`` < ``eps``. If None, ``eps`` is
-        ignored and return np.nan for ``q`` values very close to zero.
-        *New in version 0.2.0*
 
     Returns
     -------
     ndarray
-        Dewpoint temperature (K)
+        Dewpoint temperature (K). For zero ``q`` values returns np.nan.
 
 
     The computation starts with determining the the saturation vapour pressure over
@@ -873,21 +823,7 @@ def dewpoint_from_specific_humidity(q, p, eps=1e-8, out=None):
     used in :func:`saturation_vapour_pressure`.
 
     """
-    # by masking upfront we avoid RuntimeWarning when calling log() in
-    # the computation of td when q is very small
-    if out is not None:
-        q = np.asarray(q)
-        mask = q < eps
-        q[mask] = np.nan
-
-    es = vapour_pressure_from_specific_humidity(q, p)
-    td = temperature_from_saturation_vapour_pressure(es)
-
-    if out is not None and not np.isnan(out):
-        td = np.asarray(td)
-        td[mask] = out
-
-    return td
+    return temperature_from_saturation_vapour_pressure(vapour_pressure_from_specific_humidity(q, p))
 
 
 def virtual_temperature(t, q):

tests/thermo/test_thermo_array.py

@@ -334,24 +334,20 @@ def test_temperature_from_saturation_vapour_pressure_1():
 
 
 @pytest.mark.parametrize(
-    "es,kwargs,expected_values",
+    "es,expected_values",
     [
-        (4.2, {}, 219.7796336743947),
-        ([4.2, 0, 0.001, np.nan], {"eps": 1e-2, "out": 100}, [219.7796336743947, 100, 100, np.nan]),
-        ([4.2, 0, 0.001, np.nan], {"eps": 1e-2, "out": np.nan}, [219.7796336743947, np.nan, np.nan, np.nan]),
-        (0, {}, np.nan),
-        (0.001, {"eps": 1e-2, "out": 100}, 100.0),
-        (0.001, {"eps": 1e-2, "out": np.nan}, np.nan),
+        (4.2, 219.7796336743947),
+        (0, np.nan),
     ],
 )
-def test_temperature_from_saturation_vapour_pressure_2(es, kwargs, expected_values):
+def test_temperature_from_saturation_vapour_pressure_2(es, expected_values):
 
     multi = isinstance(es, list)
     if multi:
         es = np.array(es)
         expected_values = np.array(expected_values)
 
-    t = thermo.array.temperature_from_saturation_vapour_pressure(es, **kwargs)
+    t = thermo.array.temperature_from_saturation_vapour_pressure(es)
     if multi:
         np.testing.assert_allclose(t, expected_values, equal_nan=True)
     else:
@@ -448,7 +444,7 @@ def test_specific_humidity_from_relative_humidity():
 
 
 @pytest.mark.parametrize(
-    "t,r,kwargs,expected_values",
+    "t,r,expected_values",
     [
         (
             [20.0, 20, 0, 35, 5, -15, 25, 25],
@@ -462,37 +458,12 @@ def test_specific_humidity_from_relative_humidity():
                 15.4779832381,
                 0,
             ],
-            {},
             [20.0, 10, -10, 32, -15, -24, -3, np.nan],
         ),
-        (
-            [20.0, 20.0, 20.0],
-            [
-                52.5224541378,
-                0.0,
-                0.000001,
-            ],
-            {"eps": 1e-3, "out": thermo.array.celsius_to_kelvin(100)},
-            [10, 100, 100],
-        ),
-        (
-            [20.0, 20.0, 20.0],
-            [
-                52.5224541378,
-                0.0,
-                0.000001,
-            ],
-            {"eps": 1e-3, "out": np.nan},
-            [10, np.nan, np.nan],
-        ),
-        (20.0, 52.5224541378, {}, 10.0),
-        (20.0, 0.0, {"eps": 1e-3, "out": thermo.array.celsius_to_kelvin(100)}, 100),
-        (20.0, 0.000001, {"eps": 1e-3, "out": thermo.array.celsius_to_kelvin(100)}, 100),
-        (20.0, 0.0, {"eps": 1e-3, "out": np.nan}, np.nan),
-        (20, 0.000001, {"eps": 1e-3, "out": np.nan}, np.nan),
+        (20.0, 52.5224541378, 10.0),
     ],
 )
-def test_dewpoint_from_relative_humidity(t, r, kwargs, expected_values):
+def test_dewpoint_from_relative_humidity(t, r, expected_values):
     # reference was tested with an online relhum calculator at:
     # https://bmcnoldy.rsmas.miami.edu/Humidity.html
 
@@ -505,50 +476,25 @@ def test_dewpoint_from_relative_humidity(t, r, kwargs, expected_values):
     t = thermo.array.celsius_to_kelvin(t)
     v_ref = thermo.array.celsius_to_kelvin(expected_values)
 
-    td = thermo.array.dewpoint_from_relative_humidity(t, r, **kwargs)
+    td = thermo.array.dewpoint_from_relative_humidity(t, r)
     if multi:
         assert np.allclose(td, v_ref, equal_nan=True)
     else:
         assert np.isclose(td, v_ref, equal_nan=True)
 
 
 @pytest.mark.parametrize(
-    "q,p,kwargs,expected_values",
+    "q,p,expected_values",
     [
         (
             [0.0169461501, 0.0155840075, 0.0134912382, 0.0083409720, 0.0057268584, 0.0025150791, 0],
             [967.5085, 936.3775, 872.248, 756.1647, 649.157, 422.4207, 422.4207],
-            {},
             [21.78907, 19.90885, 16.50236, 7.104064, -0.3548709, -16.37916, np.nan],
         ),
-        (
-            [
-                0.0169461501,
-                0.0,
-                0.000001,
-            ],
-            [967.5085, 967.5085, 967.5085],
-            {"eps": 1e-3, "out": thermo.array.celsius_to_kelvin(100)},
-            [21.78907, 100, 100],
-        ),
-        (
-            [
-                0.0169461501,
-                0.0,
-                0.000001,
-            ],
-            [967.5085, 967.5085, 967.5085],
-            {"eps": 1e-3, "out": np.nan},
-            [21.78907, np.nan, np.nan],
-        ),
-        (0.0169461501, 967.508, {}, 21.78907),
-        (0.0, 967.5085, {"eps": 1e-3, "out": thermo.array.celsius_to_kelvin(100)}, 100),
-        (0.000001, 967.5085, {"eps": 1e-3, "out": thermo.array.celsius_to_kelvin(100)}, 100),
-        (0.0, 967.5085, {"eps": 1e-3, "out": np.nan}, np.nan),
-        (0.000001, 967.5085, {"eps": 1e-3, "out": np.nan}, np.nan),
+        (0.0169461501, 967.508, 21.78907),
     ],
 )
-def test_dewpoint_from_specific_humidity(q, p, kwargs, expected_values):
+def test_dewpoint_from_specific_humidity(q, p, expected_values):
     multi = isinstance(q, list)
     if multi:
         q = np.array(q)
@@ -558,7 +504,7 @@ def test_dewpoint_from_specific_humidity(q, p, kwargs, expected_values):
     p = p * 100.0
     v_ref = thermo.array.celsius_to_kelvin(expected_values)
 
-    td = thermo.array.dewpoint_from_specific_humidity(q, p, **kwargs)
+    td = thermo.array.dewpoint_from_specific_humidity(q, p)
     if multi:
         assert np.allclose(td, v_ref, equal_nan=True)
     else: