use mean, move _gamma, make sure _gamma is frac not percentage

api/solarperformanceinsight_api/compute.py

@@ -5,6 +5,7 @@
 from itertools import zip_longest
 import json
 import logging
+from statistics import mean
 from typing import Callable, Generator, Union, List, Tuple, Optional
 from uuid import UUID
 
@@ -621,7 +622,8 @@ def _calculate_weather_adjusted_predicted_performance(
         pac0 = inv.inverter_parameters._pac0
         num_arrays = len(chain.system.arrays)
         gammas = [
-            arr._gamma for arr in job.definition.system_definition.inverters[i].arrays
+            arr.module_parameters._gamma
+            for arr in job.definition.system_definition.inverters[i].arrays
         ]
         if any([g is None for g in gammas]):
             raise TypeError(
@@ -753,19 +755,19 @@ def compare_monthly_predicted_and_actual(
     pac0 = sum([inv.inverter_parameters._pac0 for inv in inverters])
     G_0 = 1000
 
-    gammas = [arr._gamma for inv in inverters for arr in inv.arrays]
+    gammas = [arr.module_parameters._gamma for inv in inverters for arr in inv.arrays]
     if any([g is None for g in gammas]):
         raise TypeError(
             "Currently unable to compare predicted and actual performance for "
             "PVsyst specified arrays."
         )
 
-    avg_gamma = sum(
+    avg_gamma = mean(
         [
-            sum([arr._gamma for arr in inv.arrays]) / len(inv.arrays)  # type: ignore
+            mean([arr.module_parameters._gamma for arr in inv.arrays])
             for inv in inverters
         ]
-    ) / len(inverters)
+    )
     poa_insol_rat = (
         actual_weather["total_poa_insolation"] / ref_weather["total_poa_insolation"]
     )

api/solarperformanceinsight_api/models.py

@@ -203,6 +203,7 @@ class PVsystModuleParameters(PVLibBase):
         gt=0,
     )
     _modelchain_dc_model: str = PrivateAttr("pvsyst")
+    _gamma: Optional[float] = PrivateAttr(None)
 
 
 class PVWattsModuleParameters(PVLibBase):
@@ -220,6 +221,11 @@ class PVWattsModuleParameters(PVLibBase):
         ),
     )
     _modelchain_dc_model: str = PrivateAttr("pvwatts")
+    _gamma: float = PrivateAttr()
+
+    def __init__(self, **data):
+        super().__init__(**data)
+        self._gamma = self.gamma_pdc / 100
 
     def pvlib_dict(self):
         """Convert to a dict pvlib understands for `module_parameters`
@@ -300,6 +306,11 @@ class CECModuleParameters(PVLibBase):
         ),
     )
     _modelchain_dc_model: str = PrivateAttr("cec")
+    _gamma: float = PrivateAttr()
+
+    def __init__(self, **data):
+        super().__init__(**data)
+        self._gamma = self.gamma_r / 100
 
     def pvlib_dict(self):
         """Convert to a dict pvlib understands for `module_parameters` by removing
@@ -382,7 +393,6 @@ class PVArray(SPIBase):
         ..., description="Number of parallel strings in the array", gt=0
     )
     _modelchain_models: Tuple[Tuple[str, str], ...] = PrivateAttr()
-    _gamma: Optional[float] = PrivateAttr(None)
 
     def __init__(self, **data):
         super().__init__(**data)
@@ -393,10 +403,6 @@ def __init__(self, **data):
                 self.temperature_model_parameters._modelchain_temperature_model,
             ),
         )
-        if isinstance(self.module_parameters, PVWattsModuleParameters):
-            self._gamma = self.module_parameters.gamma_pdc
-        elif isinstance(self.module_parameters, CECModuleParameters):
-            self._gamma = self.module_parameters.gamma_r
 
 
 class PVWattsLosses(SPIBase):

api/solarperformanceinsight_api/tests/test_compute.py

@@ -832,9 +832,9 @@ def test_compare_monthly_predicted_and_actual(
     assert len(ser) == 5
     assert ser.loc["month"] == "July"
     assert ser.loc["actual_energy"] == 60000
-    assert ser.loc["weather_adjusted_energy"] == 56212.5
-    assert ser.loc["difference"] == 3787.5
-    assert (ser.loc["ratio"] - 1.0673783) < 1e-7
+    assert ser.loc["weather_adjusted_energy"] == 56249.625
+    assert ser.loc["difference"] == 3750.375
+    assert (ser.loc["ratio"] - 1.0666738) < 1e-10
 
 
 @pytest.fixture(params=list(models.TemperatureTypeEnum))
@@ -1091,7 +1091,7 @@ def test_compare_predicted_and_actual(
     )
     assert ser["weather_adjusted_energy"] > 0
     assert "difference" in ser
-    assert 0.5 < ser["ratio"] < 1.5
+    assert 0.5 < ser["ratio"] < 1.8
 
 
 @pytest.mark.parametrize(

api/solarperformanceinsight_api/tests/test_models.py

@@ -711,12 +711,12 @@ def test_array_gamma(system_def):
     )
     arrd = deepcopy(system_def.inverters[0].arrays[0].dict())
     mod = models.PVArray(**arrd)
-    assert mod._gamma is None  # PVsyst
+    assert mod.module_parameters._gamma is None  # PVsyst
 
     arrd["module_parameters"] = cec
     mod = models.PVArray(**arrd)
-    assert mod._gamma == -0.487
+    assert mod.module_parameters._gamma == -4.87e-3
 
     arrd["module_parameters"] = {"pdc0": 100, "gamma_pdc": -0.328}
     mod = models.PVArray(**arrd)
-    assert mod._gamma == -0.328
+    assert mod.module_parameters._gamma == -3.28e-3