Normalized filter cherrypick

docs/degradation_and_soiling_example.ipynb

@@ -252,14 +252,14 @@
    "source": [
     "# Calculate a collection of boolean masks that can be used\n",
     "# to filter the time series\n",
-    "nz_mask = (df['normalized'] > 0.01)\n",
+    "normalized_mask = rdtools.normalized_filter(df['normalized'])\n",
     "poa_mask = rdtools.poa_filter(df['poa'])\n",
     "tcell_mask = rdtools.tcell_filter(df['Tcell'])\n",
     "clip_mask = rdtools.clip_filter(df['power'])\n",
     "\n",
     "# filter the time series and keep only the columns needed for the\n",
     "# remaining steps\n",
-    "filtered = df[nz_mask & poa_mask & tcell_mask & clip_mask]\n",
+    "filtered = df[normalized_mask & poa_mask & tcell_mask & clip_mask]\n",
     "filtered = filtered[['insolation', 'normalized']]\n",
     "\n",
     "fig, ax = plt.subplots()\n",
@@ -709,14 +709,14 @@
    "outputs": [],
    "source": [
     "# Perform clearsky filter\n",
-    "cs_nz_mask = (df['clearsky_normalized'] > 0.01)\n",
+    "cs_normalized_mask = rdtools.normalized_filter(df['clearsky_normalized'])\n",
     "cs_poa_mask = rdtools.poa_filter(df['clearsky_poa'])\n",
     "cs_tcell_mask = rdtools.tcell_filter(df['clearsky_Tcell'])\n",
     "\n",
     "csi_mask = rdtools.csi_filter(df.insolation, df.clearsky_insolation)\n",
     "\n",
     "\n",
-    "clearsky_filtered = df[cs_nz_mask & cs_poa_mask & cs_tcell_mask & clip_mask & csi_mask]\n",
+    "clearsky_filtered = df[cs_normalized_mask & cs_poa_mask & cs_tcell_mask & clip_mask & csi_mask]\n",
     "clearsky_filtered = clearsky_filtered[['clearsky_insolation', 'clearsky_normalized']]"
    ]
   },

docs/sphinx/source/api.rst

@@ -61,6 +61,7 @@ Functions to perform filtering on PV system data.
    filtering.csi_filter
    filtering.poa_filter
    filtering.tcell_filter
+   filtering.normalized_filter
 
 
 Normalization

docs/sphinx/source/changelog/v2.0.0.rst

@@ -12,6 +12,7 @@ Enhancements
   recovery method (:pull:`112`).
 * Add new functions :py:func:`~rdtools.normalization.energy_from_power` and
   :py:func:`~rdtools.normalization.interpolate`.
+* Add new function :py:func:`~rdtools.filtering.normalized_filter`.
 * Add new :py:mod:`~rdtools.plotting` module for generating standard plots.
 * Add parameter ``convergence_threshold`` to
   :py:func:`~rdtools.normalization.irradiance_rescale` (:pull:`152`).
@@ -41,6 +42,9 @@ Requirements
 Example Updates
 ---------------
 * Seed ``numpy.random`` to ensure repeatable results (:pull:`164`).
+* Use :py:func:`~rdtools.filtering.normalized_filter` instead of manually
+  filtering the normalized energy timeseries.  Also updated the associated mask
+  variable names (:pull:`139`).
 
 Contributors
 ------------

rdtools/__init__.py

@@ -12,6 +12,7 @@
 from rdtools.filtering import poa_filter
 from rdtools.filtering import tcell_filter
 from rdtools.filtering import clip_filter
+from rdtools.filtering import normalized_filter
 from rdtools.soiling import soiling_srr
 from rdtools.plotting import degradation_summary_plots
 from rdtools.plotting import soiling_monte_carlo_plot

rdtools/filtering.py

@@ -1,5 +1,35 @@
 '''Functions for filtering and subsetting PV system data.'''
 
+import numpy as np
+
+
+def normalized_filter(normalized, low_cutoff=0.01, high_cutoff=None):
+    '''
+    Select normalized yield between ``low_cutoff`` and ``high_cutoff``
+
+    Parameters
+    ----------
+    normalized : pd.Series
+        Normalized power measurements.
+    low_cutoff : float, default 0.01
+        The lower bound of acceptable values.
+    high_cutoff : float, optional
+        The upper bound of acceptable values.
+
+    Returns
+    -------
+    pd.Series
+        Boolean Series of whether the given measurement is within acceptable
+        bounds.
+    '''
+
+    if low_cutoff is None:
+        low_cutoff = -np.inf
+    if high_cutoff is None:
+        high_cutoff = np.inf
+
+    return (normalized > low_cutoff) & (normalized < high_cutoff)
+
 
 def poa_filter(poa, low_irradiance_cutoff=200, high_irradiance_cutoff=1200):
     '''

rdtools/test/filtering_test.py

@@ -5,7 +5,7 @@
 import pandas as pd
 import numpy as np
 
-from rdtools import csi_filter, poa_filter, tcell_filter, clip_filter
+from rdtools import csi_filter, poa_filter, tcell_filter, clip_filter, normalized_filter
 
 
 class CSIFilterTestCase(unittest.TestCase):
@@ -73,5 +73,18 @@ def test_clip_filter_upper(self):
         self.assertTrue((expected_result == filtered).all())
 
 
+def test_normalized_filter_default():
+    pd.testing.assert_series_equal(normalized_filter(pd.Series([-5, 5])),
+                                   pd.Series([False, True]))
+
+    pd.testing.assert_series_equal(normalized_filter(pd.Series([-1e6, 1e6]), low_cutoff=None, high_cutoff=None),
+                                   pd.Series([True, True]))
+
+    pd.testing.assert_series_equal(normalized_filter(pd.Series([-2, 2]), low_cutoff=-1, high_cutoff=1),
+                                   pd.Series([False, False]))
+
+    pd.testing.assert_series_equal(normalized_filter(pd.Series([0.01 - 1e-16, 0.01 + 1e-16, 1e308])),
+                                   pd.Series([False, True, True]))
+
 if __name__ == '__main__':
     unittest.main()