reduce boilerplate code in physics by introducing plus-separated Formulae ctor args (#1314)

Author: slayoo

PySDM/formulae.py

@@ -224,7 +224,7 @@ def _formula(func, constants, dimensional_analysis, **kw):
 
 def _boost(obj, fastmath, constants, dimensional_analysis):
     """returns JIT-compiled, `c_inline`-equipped formulae with the constants catalogue attached"""
-    formulae = {"__name__": obj.__class__.__name__}
+    formulae = {"__name__": obj.__name__}
     for item in dir(obj):
         attr = getattr(obj, item)
         if item.startswith("__") or not callable(attr):
@@ -288,13 +288,40 @@ def _c_inline(fun, return_type=None, constants=None, **args):
 
 
 def _pick(value: str, choices: dict, constants: namedtuple):
-    """selects a given physics logic and instantiates it passing the constants catalogue"""
-    for name, cls in choices.items():
-        if name == value:
-            return cls(constants)
-    raise ValueError(
-        f"Unknown setting: '{value}'; choices are: {tuple(choices.keys())}"
-    )
+    """
+    selects a given physics logic and instantiates it passing the constants catalogue;
+    `value` is expected to be string containing a plus-separated list of class names
+    """
+
+    obj = None
+    if "+" not in value:
+        for name, cls in choices.items():
+            if name == value:
+                obj = cls(constants)
+    else:
+        parent_classes = []
+        for name in value.split("+"):
+            if name not in choices:
+                parent_classes.clear()
+                break
+            parent_classes.append(choices[name])
+
+        if len(parent_classes) > 0:
+
+            class Cls(*parent_classes):  # pylint: disable=too-few-public-methods
+                def __init__(self, const):
+                    for cls in parent_classes:
+                        cls.__init__(self, const)
+
+            obj = Cls(constants)
+
+    if obj is None:
+        raise ValueError(
+            f"Unknown setting: '{name}'; choices are: {tuple(choices.keys())}"
+        )
+
+    obj.__name__ = value  # pylint: disable=attribute-defined-outside-init
+    return obj
 
 
 def _choices(module):

PySDM/physics/isotope_equilibrium_fractionation_factors/__init__.py

@@ -2,14 +2,11 @@
 phase equilibrium, defined as ratios alpha of isotopic ratios R """
 
 from .barkan_and_luz_2005 import BarkanAndLuz2005
-from .bolot_et_al_2013 import BolotEtAl2013
-from .graf_phd_2017 import GrafPhD2017
 from .horita_and_wesolowski_1994 import HoritaAndWesolowski1994
 from .majoube_1970 import Majoube1970
 from .majoube_1971 import Majoube1971
 from .merlivat_and_nief_1967 import MerlivatAndNief1967
 from .null import Null
-from .pierchala_et_al_2022 import PierchalaEtAl2022
 from .van_hook_1968 import VanHook1968
 from .lamb_et_al_2017 import LambEtAl2017
 from .ellehoj_et_al_2013 import EllehojEtAl2013

PySDM/physics/isotope_equilibrium_fractionation_factors/bolot_et_al_2013.py

@@ -3,4 +3,3 @@
 from .barkan_and_luz_2007 import BarkanAndLuz2007
 from .dansgaard_1964 import Dansgaard1964
 from .null import Null
-from .pierchala_et_al_2022 import PierchalaEtAl2022

PySDM/physics/isotope_equilibrium_fractionation_factors/graf_phd_2017.py

@@ -67,7 +67,7 @@
    },
    "outputs": [],
    "source": [
-    "formulae = Formulae(isotope_equilibrium_fractionation_factors=\"BolotEtAl2013\")\n",
+    "formulae = Formulae(isotope_equilibrium_fractionation_factors=\"MerlivatAndNief1967+Majoube1970+Majoube1971\")\n",
     "alphas = formulae.isotope_equilibrium_fractionation_factors\n",
     "const = formulae.constants"
    ]

PySDM/physics/isotope_equilibrium_fractionation_factors/pierchala_et_al_2022.py

@@ -57,7 +57,7 @@
    "outputs": [],
    "source": [
     "formulae = Formulae(\n",
-    "    isotope_equilibrium_fractionation_factors='GrafPhD2017',\n",
+    "    isotope_equilibrium_fractionation_factors='Majoube1970+Majoube1971+MerlivatAndNief1967',\n",
     "    isotope_meteoric_water_line_excess='Dansgaard1964'\n",
     ")\n",
     "const = formulae.constants\n",

PySDM/physics/isotope_meteoric_water_line_excess/__init__.py

@@ -70,8 +70,8 @@
    "outputs": [],
    "source": [
     "formulae = Formulae(\n",
-    "    isotope_equilibrium_fractionation_factors='PierchalaEtAl2022',\n",
-    "    isotope_meteoric_water_line_excess='PierchalaEtAl2022',\n",
+    "    isotope_equilibrium_fractionation_factors='BarkanAndLuz2005+HoritaAndWesolowski1994',\n",
+    "    isotope_meteoric_water_line_excess='Dansgaard1964+BarkanAndLuz2007',\n",
     "    isotope_ratio_evolution='RayleighDistillation'\n",
     ")\n",
     "const = formulae.constants\n",