degradation: time dependent integral

NREL · Dec 18, 2024 · 131337a · 131337a
1 parent 0ee3550
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diff --git a/pvdeg/degradation.py b/pvdeg/degradation.py
@@ -864,6 +864,7 @@ def _gJtoMJ(gJ):
 
 
 # new version of degradation
+# we can make this work with varying timedelta sizes
 def degradation(
     spectra_df: pd.DataFrame,
     conditions_df: pd.DataFrame = None,
@@ -878,7 +879,8 @@ def degradation(
     """
     Compute degredation as double integral of Arrhenius (Activation
     Energy, RH, Temperature) and spectral (wavelength, irradiance)
-    functions over wavelength and time.
+    functions over wavelength and time. Using dataframe input with
+    pd.TimeIndex with constant timedelta.
 
     .. math::
 
@@ -890,7 +892,7 @@ def degradation(
         front or rear irradiance data in dataframe format
 
         - `data`: Spectral irradiance values for each wavelength [W/m^2 nm].
-        - `index`: pd.DateTimeIndex
+        - `index`: pd.DateTimeIndex with constant timedelta
         - `columns`: Wavelengths as floats (e.g., 280, 300, etc.) [nm].
 
         Example::
@@ -904,9 +906,9 @@ def degradation(
     conditions_df : pd.DataFrame, optional
         Environmental conditions including temperature and relative humidity.
 
-        - `index`: pd.DateTimeIndex
+        - `index`: pd.DateTimeIndex identical to spectra_df.index
         - `columns`:  (required)
-            - "temperature" [°C or K]
+            - "temperature" [°K]
             - "relative_humidity" [%]
 
         Example::
@@ -946,7 +948,8 @@ def degradation(
     degradation : float
         Total degredation factor over time and wavelength.
     """
-
+    if not isinstance(spectra_df.index, pd.DatetimeIndex):
+        raise ValueError(f"spectra_df must have pd.DatetimeIndex, has {type(spectra_df.index)}")
 
     if conditions_df is not None and (temp_module is not None or rh_module is not None):
         raise ValueError("Provide either conditions_df or temp_module and rh_module")
@@ -960,26 +963,29 @@ def degradation(
 
     wavelengths = spectra_df.columns.values.astype(float)
     irr = spectra_df.values  # irradiance as array
+    dt = (spectra_df.index[1] - spectra_df.index[0]).total_seconds() / 3600.0
 
     # call numba compiled function
     return deg(
         wavelengths=wavelengths, 
         irr=irr,
         rh=rh, 
         temps=temps, 
+        dt=dt,
         Ea=Ea, 
         C2=C2, 
         p=p, 
         n=n, 
         C=C
     )
 
-@njit 
+# @njit 
 def deg(
     wavelengths: np.ndarray, 
     irr: np.ndarray, 
     rh: np.ndarray, 
     temps: np.ndarray, 
+    dt: float, # timestep in hours 
     Ea: float, 
     C2: float, 
     p: float, 
@@ -1003,7 +1009,7 @@ def deg(
     # arrhenius integral dt
     time_integrand = (rh ** n) * np.exp(-Ea / (R * temps))
 
-    dD = wavelength_integral * time_integrand
+    dD = wavelength_integral * time_integrand * dt
     degradation = C * np.sum(dD)
 
     return degradation

diff --git a/tests/sandbox.ipynb b/tests/sandbox.ipynb
@@ -813,24 +813,9 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {},
-   "outputs": [
-    {
-     "ename": "Failed",
-     "evalue": "Invalid regex pattern provided to 'match': incomplete escape \\U at position 46",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[1;31mFailed\u001b[0m                                    Traceback (most recent call last)",
-      "Cell \u001b[1;32mIn[3], line 10\u001b[0m\n\u001b[0;32m      4\u001b[0m invalid_name_or_alias \u001b[38;5;241m=\u001b[39m \u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mnamenotindict\u001b[39m\u001b[38;5;124m\"\u001b[39m\n\u001b[0;32m      5\u001b[0m expected_error_message \u001b[38;5;241m=\u001b[39m (\n\u001b[0;32m      6\u001b[0m     \u001b[38;5;124mrf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mname_or_alias: \u001b[39m\u001b[38;5;132;01m{\u001b[39;00minvalid_name_or_alias\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m not in JSON at \u001b[39m\u001b[38;5;124m\"\u001b[39m\n\u001b[0;32m      7\u001b[0m     \u001b[38;5;124mrf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;132;01m{\u001b[39;00mos\u001b[38;5;241m.\u001b[39mpath\u001b[38;5;241m.\u001b[39mjoin(DATA_DIR,\u001b[38;5;250m \u001b[39mpvdeg\u001b[38;5;241m.\u001b[39mutilities\u001b[38;5;241m.\u001b[39mpvdeg_datafiles[pvdeg_file])\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m\"\u001b[39m\n\u001b[0;32m      8\u001b[0m )\n\u001b[1;32m---> 10\u001b[0m \u001b[38;5;28;01mwith\u001b[39;00m \u001b[43mpytest\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mraises\u001b[49m\u001b[43m(\u001b[49m\u001b[38;5;167;43;01mValueError\u001b[39;49;00m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mmatch\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mexpected_error_message\u001b[49m\u001b[43m)\u001b[49m:\n\u001b[0;32m     11\u001b[0m     pvdeg\u001b[38;5;241m.\u001b[39mutilities\u001b[38;5;241m.\u001b[39msearch_json(pvdeg_file\u001b[38;5;241m=\u001b[39mpvdeg_file, name_or_alias\u001b[38;5;241m=\u001b[39minvalid_name_or_alias)\n",
-      "    \u001b[1;31m[... skipping hidden 1 frame]\u001b[0m\n",
-      "File \u001b[1;32mc:\\Users\\tford\\AppData\\Local\\miniconda3\\envs\\deg\\lib\\site-packages\\_pytest\\python_api.py:997\u001b[0m, in \u001b[0;36mRaisesContext.__init__\u001b[1;34m(self, expected_exception, message, match_expr)\u001b[0m\n\u001b[0;32m    995\u001b[0m     re_error \u001b[38;5;241m=\u001b[39m e\n\u001b[0;32m    996\u001b[0m \u001b[38;5;28;01mif\u001b[39;00m re_error \u001b[38;5;129;01mis\u001b[39;00m \u001b[38;5;129;01mnot\u001b[39;00m \u001b[38;5;28;01mNone\u001b[39;00m:\n\u001b[1;32m--> 997\u001b[0m     \u001b[43mfail\u001b[49m\u001b[43m(\u001b[49m\u001b[38;5;124;43mf\u001b[39;49m\u001b[38;5;124;43m\"\u001b[39;49m\u001b[38;5;124;43mInvalid regex pattern provided to \u001b[39;49m\u001b[38;5;124;43m'\u001b[39;49m\u001b[38;5;124;43mmatch\u001b[39;49m\u001b[38;5;124;43m'\u001b[39;49m\u001b[38;5;124;43m: \u001b[39;49m\u001b[38;5;132;43;01m{\u001b[39;49;00m\u001b[43mre_error\u001b[49m\u001b[38;5;132;43;01m}\u001b[39;49;00m\u001b[38;5;124;43m\"\u001b[39;49m\u001b[43m)\u001b[49m\n",
-      "File \u001b[1;32mc:\\Users\\tford\\AppData\\Local\\miniconda3\\envs\\deg\\lib\\site-packages\\_pytest\\outcomes.py:178\u001b[0m, in \u001b[0;36mfail\u001b[1;34m(reason, pytrace)\u001b[0m\n\u001b[0;32m    165\u001b[0m \u001b[38;5;250m\u001b[39m\u001b[38;5;124;03m\"\"\"Explicitly fail an executing test with the given message.\u001b[39;00m\n\u001b[0;32m    166\u001b[0m \n\u001b[0;32m    167\u001b[0m \u001b[38;5;124;03m:param reason:\u001b[39;00m\n\u001b[1;32m   (...)\u001b[0m\n\u001b[0;32m    175\u001b[0m \u001b[38;5;124;03m    The exception that is raised.\u001b[39;00m\n\u001b[0;32m    176\u001b[0m \u001b[38;5;124;03m\"\"\"\u001b[39;00m\n\u001b[0;32m    177\u001b[0m __tracebackhide__ \u001b[38;5;241m=\u001b[39m \u001b[38;5;28;01mTrue\u001b[39;00m\n\u001b[1;32m--> 178\u001b[0m \u001b[38;5;28;01mraise\u001b[39;00m Failed(msg\u001b[38;5;241m=\u001b[39mreason, pytrace\u001b[38;5;241m=\u001b[39mpytrace)\n",
-      "\u001b[1;31mFailed\u001b[0m: Invalid regex pattern provided to 'match': incomplete escape \\U at position 46"
-     ]
-    }
-   ],
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
    "source": [
     "from pvdeg import DATA_DIR\n",
     "\n",
@@ -847,21 +832,9 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": null,
    "metadata": {},
-   "outputs": [
-    {
-     "ename": "NameError",
-     "evalue": "name 'invalid_name_or_alias' is not defined",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[1;31mNameError\u001b[0m                                 Traceback (most recent call last)",
-      "Cell \u001b[1;32mIn[2], line 2\u001b[0m\n\u001b[0;32m      1\u001b[0m expected_error_message \u001b[38;5;241m=\u001b[39m (\n\u001b[1;32m----> 2\u001b[0m     \u001b[38;5;124mrf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mname_or_alias: \u001b[39m\u001b[38;5;132;01m{\u001b[39;00minvalid_name_or_alias\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m not in JSON at \u001b[39m\u001b[38;5;124m\"\u001b[39m\n\u001b[0;32m      3\u001b[0m     \u001b[38;5;124mrf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;132;01m{\u001b[39;00mos\u001b[38;5;241m.\u001b[39mpath\u001b[38;5;241m.\u001b[39mjoin(DATA_DIR,\u001b[38;5;250m \u001b[39mpvdeg\u001b[38;5;241m.\u001b[39mutilities\u001b[38;5;241m.\u001b[39mpvdeg_datafiles[pvdeg_file])\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m\"\u001b[39m\n\u001b[0;32m      4\u001b[0m )\n",
-      "\u001b[1;31mNameError\u001b[0m: name 'invalid_name_or_alias' is not defined"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "\n",
     "expected_error_message = (\n",
@@ -872,46 +845,74 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": null,
    "metadata": {},
-   "outputs": [
-    {
-     "data": {
-      "text/plain": [
-       "'name_or_alias: namenotindict not in JSON at C:\\\\Users\\\\tford\\\\dev\\\\PVDegradationTools\\\\pvdeg\\\\data\\\\H2Opermeation.json'"
-      ]
-     },
-     "execution_count": 4,
-     "metadata": {},
-     "output_type": "execute_result"
-    }
-   ],
+   "outputs": [],
    "source": [
     "expected_error_message"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": null,
    "metadata": {},
-   "outputs": [
-    {
-     "ename": "TypeError",
-     "evalue": "'module' object is not callable",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
-      "\u001b[1;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
-      "Cell \u001b[1;32mIn[5], line 1\u001b[0m\n\u001b[1;32m----> 1\u001b[0m \u001b[43mpvdeg\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mutilities\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43msearch_json\u001b[49m\u001b[43m(\u001b[49m\u001b[43mpvdeg_file\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43mpvdeg_file\u001b[49m\u001b[43m,\u001b[49m\u001b[43m \u001b[49m\u001b[43mname_or_alias\u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43minvalid_name_or_alias\u001b[49m\u001b[43m)\u001b[49m\n",
-      "File \u001b[1;32m~\\dev\\PVDegradationTools\\pvdeg\\utilities.py:1437\u001b[0m, in \u001b[0;36msearch_json\u001b[1;34m(pvdeg_file, fp, name_or_alias)\u001b[0m\n\u001b[0;32m   1434\u001b[0m         \u001b[38;5;28;01mif\u001b[39;00m (subdict[\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mname\u001b[39m\u001b[38;5;124m\"\u001b[39m] \u001b[38;5;241m==\u001b[39m name_or_alias \u001b[38;5;129;01mor\u001b[39;00m subdict[\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124malias\u001b[39m\u001b[38;5;124m\"\u001b[39m] \u001b[38;5;241m==\u001b[39m name_or_alias):\n\u001b[0;32m   1435\u001b[0m             \u001b[38;5;28;01mreturn\u001b[39;00m key\n\u001b[1;32m-> 1437\u001b[0m \u001b[38;5;28;01mraise\u001b[39;00m \u001b[38;5;167;01mValueError\u001b[39;00m(\u001b[38;5;124mrf\u001b[39m\u001b[38;5;124m\"\u001b[39m\u001b[38;5;124mname_or_alias: \u001b[39m\u001b[38;5;132;01m{\u001b[39;00mname_or_alias\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m not in JSON at \u001b[39m\u001b[38;5;132;01m{\u001b[39;00mos\u001b[38;5;241m.\u001b[39mpath(fp)\u001b[38;5;132;01m}\u001b[39;00m\u001b[38;5;124m\"\u001b[39m)\n",
-      "\u001b[1;31mTypeError\u001b[0m: 'module' object is not callable"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "pvdeg.utilities.search_json(pvdeg_file=pvdeg_file, name_or_alias=invalid_name_or_alias)"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import os\n",
+    "import pandas as pd\n",
+    "import pvdeg\n",
+    "import numpy as np\n",
+    "from pvdeg import TEST_DATA_DIR\n",
+    "import pytest\n",
+    "\n",
+    "INPUT_SPECTRA = os.path.join(TEST_DATA_DIR, r\"spectra_pytest.csv\")\n",
+    "\n",
+    "data = pd.read_csv(INPUT_SPECTRA)\n",
+    "wavelengths = np.array(range(280, 420, 20))\n",
+    "\n",
+    "# convert to expected format\n",
+    "spectra = data[\"Spectra\"]\n",
+    "spectra_df = pd.DataFrame(spectra.tolist(), index=spectra.index)\n",
+    "spectra_df = spectra.str.strip(\"[]\").str.split(\",\", expand=True).astype(float)\n",
+    "spectra_df.columns = wavelengths\n",
+    "\n",
+    "# from input data, this was lost during our original conversion to the dataframe\n",
+    "spectra_df.index = pd.date_range(\"2021-03-09 10:00:00\", freq='1h', periods=10)\n",
+    "\n",
+    "conditions_df = pd.DataFrame(\n",
+    "    data={\n",
+    "        \"relative_humidity\": data[\"RH\"],\n",
+    "        \"temperature\": data[\"Temperature\"],\n",
+    "    }\n",
+    ")\n",
+    "conditions_df.index = spectra_df.index\n",
+    "\n",
+    "degradation = pvdeg.degradation.degradation(\n",
+    "    spectra_df=spectra_df,\n",
+    "    conditions_df=conditions_df\n",
+    ")\n",
+    "\n",
+    "assert degradation == pytest.approx(4.4969e-38, abs=0.02e-38)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "degradation"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,

diff --git a/tests/test_degradation.py b/tests/test_degradation.py
@@ -128,6 +128,7 @@ def test_degradation():
     # test RH, Temp, Spectral Irradiance sensitive degradation
     # requires TMY3-like weather data
     # requires spectral irradiance data
+    INPUT_SPECTRA = os.path.join(TEST_DATA_DIR, r"spectra_pytest.csv")
 
     data = pd.read_csv(INPUT_SPECTRA)
     wavelengths = np.array(range(280, 420, 20))
@@ -138,13 +139,16 @@ def test_degradation():
     spectra_df = spectra.str.strip("[]").str.split(",", expand=True).astype(float)
     spectra_df.columns = wavelengths
 
+    # from input data, this was lost during our original conversion to the dataframe
+    spectra_df.index = pd.date_range("2021-03-09 10:00:00", freq='1h', periods=10)
+
     conditions_df = pd.DataFrame(
-        index=spectra_df.index,
         data={
             "relative_humidity": data["RH"],
             "temperature": data["Temperature"],
         }
     )
+    conditions_df.index = spectra_df.index
 
     degradation = pvdeg.degradation.degradation(
         spectra_df=spectra_df,
@@ -153,7 +157,6 @@ def test_degradation():
 
     assert degradation == pytest.approx(4.4969e-38, abs=0.02e-38)
 
-
 # def test_hours_rh_above_85():
 #     values = np.arange(0,100)
 #     rh_linear_df = pd.DataFrame(values, columns=['rh'])