mixed-phase moments: new test and filtering attr name fix (#1536)

Co-authored-by: Tim Luettmer <tluettm@uni-mainz.de>
Co-authored-by: Tim Lüttmer <154344756+tluettm@users.noreply.github.com>

Author: slayoo

PySDM/particulator.py

@@ -317,7 +317,7 @@ def moments(
         moment_0,
         moments,
         specs: dict,
-        attr_name="water mass",
+        attr_name="signed water mass",
         attr_range=(-np.inf, np.inf),
         weighting_attribute="water mass",
         weighting_rank=0,

PySDM/products/impl/moment_product.py

@@ -27,7 +27,7 @@ def _download_moment_to_buffer(
         *,
         attr,
         rank,
-        filter_attr="water mass",
+        filter_attr="signed water mass",
         filter_range=(-np.inf, np.inf),
         weighting_attribute="water mass",
         weighting_rank=0,

PySDM/products/size_spectral/mean_radius.py

@@ -27,10 +27,14 @@ def _impl(self, **kwargs):
             attr="volume",
             rank=1 / 3,
             filter_range=(
-                self.formulae.trivia.volume(self.radius_range[0]),
-                self.formulae.trivia.volume(self.radius_range[1]),
+                self.formulae.particle_shape_and_density.radius_to_mass(
+                    self.radius_range[0]
+                ),
+                self.formulae.particle_shape_and_density.radius_to_mass(
+                    self.radius_range[1]
+                ),
             ),
-            filter_attr="volume",
+            filter_attr="signed water mass",
         )
         self.buffer[:] /= self.formulae.constants.PI_4_3 ** (1 / 3)
         return self.buffer

PySDM/products/size_spectral/water_mixing_ratio.py

@@ -12,30 +12,32 @@
 class WaterMixingRatio(MomentProduct):
     def __init__(self, radius_range=None, name=None, unit="dimensionless"):
         self.radius_range = radius_range or (0, np.inf)
-        self.mass_range = None
+        self.signed_mass_range = None
         super().__init__(unit=unit, name=name)
 
     def register(self, builder):
         super().register(builder)
-        self.mass_range = self.formulae.particle_shape_and_density.radius_to_mass(
-            np.asarray(self.radius_range)
+        self.signed_mass_range = (
+            self.formulae.particle_shape_and_density.radius_to_mass(
+                np.asarray(self.radius_range)
+            )
         )
         self.radius_range = None
 
     def _impl(self, **kwargs):  # TODO #217
         self._download_moment_to_buffer(
             attr="water mass",
             rank=0,
-            filter_range=self.mass_range,
-            filter_attr="water mass",
+            filter_range=self.signed_mass_range,
+            filter_attr="signed water mass",
         )
         conc = self.buffer.copy()
 
         self._download_moment_to_buffer(
             attr="water mass",
             rank=1,
-            filter_range=self.mass_range,
-            filter_attr="water mass",
+            filter_range=self.signed_mass_range,
+            filter_attr="signed water mass",
         )
         result = self.buffer.copy()
         result[:] *= conc

tests/unit_tests/products/test_mixed_phase_moments.py

@@ -66,12 +66,14 @@ def test_mixed_phase_moments(particle_mass, backend_class):
     r_t = particulator.products["r_all"].get()[0]
 
     # assert
-    assert lwc >= 0
-    assert iwc >= 0
-    assert twc >= 0
-    assert lwc + iwc == twc
-    assert n_w + n_i == n_t
-
     assert np.isfinite([lwc, iwc, twc]).all()
     assert np.isfinite([n_w, n_i, n_t]).all()
     assert np.isfinite([r_w, r_i, r_t]).all()
+
+    if any(particle_mass > 0):
+        assert all(product > 0 for product in (lwc, n_w, r_w))
+    if any(particle_mass < 0):
+        assert all(product > 0 for product in (iwc, n_i, r_i))
+    assert twc > 0
+    assert lwc + iwc == twc
+    assert n_w + n_i == n_t