* Formatting of ModelChain.diode_params into pandas.DataFrame

Author: tylunel

docs/sphinx/source/whatsnew/v0.7.0.rst

@@ -108,6 +108,8 @@ API Changes with Deprecations
   argument for capability during the deprecation period.
 * Parameter `pvsystem.DC_MODEL_PARAMS` is renamed to `pvsystem._DC_MODEL_PARAMS`.
   Users should not rely on this dictionary's existence or structure.
+* The `modelchain.ModelChain.diode_params` attribute is now formatted in
+  a pandas.DataFrame with `DatetimeIndex`, rather than in a tuple.
 
 Other API Changes
 ~~~~~~~~~~~~~~~~~

pvlib/modelchain.py

@@ -8,6 +8,7 @@
 
 from functools import partial
 import warnings
+import pandas as pd
 
 from pvlib import (atmosphere, clearsky, pvsystem, solarposition, temperature,
                    tools)
@@ -453,9 +454,11 @@ def _singlediode(self, calcparams_model_function):
             calcparams_model_function(self.effective_irradiance,
                                       self.cell_temperature))
 
-        self.diode_params = (photocurrent, saturation_current,
-                             resistance_series,
-                             resistance_shunt, nNsVth)
+        self.diode_params = pd.DataFrame({'I_L': photocurrent,
+                                          'I_o': saturation_current,
+                                          'R_s': resistance_series,
+                                          'R_sh': resistance_shunt,
+                                          'nNsVth': nNsVth})
 
         self.dc = self.system.singlediode(
             photocurrent, saturation_current, resistance_series,
@@ -926,7 +929,7 @@ def run_model(self, weather, times=None):
 
         Assigns attributes: solar_position, airmass, irradiance,
         total_irrad, effective_irradiance, weather, cell_temperature, aoi,
-        aoi_modifier, spectral_modifier, dc, ac, losses.
+        aoi_modifier, spectral_modifier, dc, ac, losses, diode_params.
         """
         if times is not None:
             warnings.warn('times keyword argument is deprecated and will be '