Clarify output variable mapping in calcparams_ functions (#2405)

* DOC: Clarify output variable mapping in calcparams_desoto, calcparams_cec, and calcparams_pvsyst

* Clean up unhelpful comment

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

* Resolve nNsVth Naming

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

* Clean up var naming comment

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

* fix: Address linting issues

* docs: Add contributor/contribution to whatsnew

---------

Co-authored-by: Cliff Hansen <cwhanse@sandia.gov>

Author: MaxJackson

docs/sphinx/source/whatsnew/v0.11.3.rst

@@ -38,7 +38,8 @@ Documentation
 * Fix Procedural and Object Oriented simulation examples having slightly different results, in :ref:`introtutorial`. (:issue:`2366`, :pull:`2367`)
 * Restructure the user guide with subsections (:issue:`2302`, :pull:`2310`)
 * Add references for :py:func:`pvlib.snow.loss_townsend`. (:issue:`2383`, :pull:`2384`)
-* Add :term:`ghi_clear` to the :ref:`nomenclature` page (:issue:`2272`, :pull`2397`)
+* Add :term:`ghi_clear` to the :ref:`nomenclature` page (:issue:`2272`, :pull:`2397`)
+* Add output variable naming clarifaction to :py:func:`pvlib.pvsystem.calcparams_desoto` and :py:func:`pvlib.pvsystem.calcparams_pvsyst` (:issue:`716`, :pull:`2405`)
 
 Testing
 ~~~~~~~
@@ -78,3 +79,4 @@ Contributors
 * Kevin Anderson (:ghuser:`kandersolar`)
 * Echedey Luis (:ghuser:`echedey-ls`)
 * Mark Campanelli (:ghuser:`markcampanelli`)
+* Max Jackson (:ghuser:`MaxJackson`)

pvlib/pvsystem.py

@@ -1709,6 +1709,8 @@ def calcparams_desoto(effective_irradiance, temp_cell,
     Rs = R_s
 
     numeric_args = (effective_irradiance, temp_cell)
+    # IL: photocurrent, I0: saturation_current, Rs: resistance_series,
+    # Rsh: resistance_shunt
     out = (IL, I0, Rs, Rsh, nNsVth)
 
     if all(map(np.isscalar, numeric_args)):
@@ -1975,6 +1977,8 @@ def calcparams_pvsyst(effective_irradiance, temp_cell,
     Rs = R_s
 
     numeric_args = (effective_irradiance, temp_cell)
+    # IL: photocurrent, I0: saturation_current, Rs: resistance_series,
+    # Rsh: resistance_shunt
     out = (IL, I0, Rs, Rsh, nNsVth)
 
     if all(map(np.isscalar, numeric_args)):