Minor edits to introtutorial.rst and pvsystem.rst for Mount (#1267)

* simple edits

* whatsnew

Author: kandersolar

docs/sphinx/source/introtutorial.rst

@@ -154,21 +154,25 @@ to accomplish our system modeling goal:
 
 .. _object-oriented:
 
-Object oriented (Location, PVSystem, ModelChain)
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-The first object oriented paradigm uses a model where a
-:py:class:`~pvlib.pvsystem.PVSystem` object represents an assembled
-collection of modules, inverters, etc., a
-:py:class:`~pvlib.location.Location` object represents a particular
-place on the planet, and a :py:class:`~pvlib.modelchain.ModelChain`
-object describes the modeling chain used to calculate PV output at that
-Location. This can be a useful paradigm if you prefer to think about the
+Object oriented (Location, Mount, Array, PVSystem, ModelChain)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The object oriented paradigm uses a model with three main concepts:
+
+1. System design (modules, inverters etc.) is represented by
+   :py:class:`~pvlib.pvsystem.PVSystem`, :py:class:`~pvlib.pvsystem.Array`,
+   and :py:class:`~pvlib.pvsystem.FixedMount`
+   /:py:class:`~pvlib.pvsystem.SingleAxisTrackerMount` objects.
+2. A particular place on the planet is represented by a
+   :py:class:`~pvlib.location.Location` object.
+3. The modeling chain used to calculate power output for a particular
+   system and location is represented by a
+   :py:class:`~pvlib.modelchain.ModelChain` object.
+
+This can be a useful paradigm if you prefer to think about the
 PV system and its location as separate concepts or if you develop your
 own ModelChain subclasses. It can also be helpful if you make extensive
-use of Location-specific methods for other calculations. pvlib-python
-also includes a :py:class:`~pvlib.tracking.SingleAxisTracker` class that
-is a subclass of :py:class:`~pvlib.pvsystem.PVSystem`.
+use of Location-specific methods for other calculations.
 
 The following code demonstrates how to use
 :py:class:`~pvlib.location.Location`,
@@ -179,14 +183,14 @@ that can provide default selections for models and can also fill
 necessary input with modeled data. For example, no air temperature
 or wind speed data is provided in the input *weather* DataFrame,
 so the ModelChain object defaults to 20 C and 0 m/s. Also, no irradiance
-transposition model is specified (keyword argument `transposition` for
+transposition model is specified (keyword argument `transposition_model` for
 ModelChain) so the ModelChain defaults to the `haydavies` model. In this
 example, ModelChain infers the DC power model from the module provided
 by examining the parameters defined for the module.
 
 .. ipython:: python
 
-    from pvlib.pvsystem import PVSystem
+    from pvlib.pvsystem import PVSystem, Array, FixedMount
     from pvlib.location import Location
     from pvlib.modelchain import ModelChain
 
@@ -200,14 +204,13 @@ by examining the parameters defined for the module.
             altitude=altitude,
             tz=timezone,
         )
-        system = PVSystem(
-            surface_tilt=latitude,
-            surface_azimuth=180,
+        mount = FixedMount(surface_tilt=latitude, surface_azimuth=180)
+        array = Array(
+            mount=mount,
             module_parameters=module,
-            inverter_parameters=inverter,
             temperature_model_parameters=temperature_model_parameters,
         )
-
+        system = PVSystem(arrays=[array], inverter_parameters=inverter)
         mc = ModelChain(system, location)
         mc.run_model(weather)
         annual_energy = mc.results.ac.sum()

docs/sphinx/source/pvsystem.rst

@@ -19,11 +19,13 @@ PV modules in the :py:class:`~pvlib.pvsystem.PVSystem`. An instance of
 multiple instances of :py:class:`~pvlib.pvsystem.Array`. An instance of the
 Array class represents a group of modules with the same orientation and
 module type. Different instances of Array can have different tilt, orientation,
-and number or type of modules.
+and number or type of modules, where the orientation is defined by the
+Array's mount (a :py:class:`~pvlib.pvsystem.FixedMount`,
+:py:class:`~pvlib.pvsystem.SingleAxisTrackerMount`, or other).
 
 The :py:class:`~pvlib.pvsystem.PVSystem` class methods wrap many of the
-functions in the :py:mod:`~pvlib.pvsystem` module. Similarly,
-:py:class:`~pvlib.pvsystem.Array` wraps several functions with its class
+functions in the :py:mod:`~pvlib.pvsystem` module. Similarly, the Mount classes
+and :py:class:`~pvlib.pvsystem.Array` wrap several functions with their class
 methods.  Methods that wrap functions have similar names as the wrapped functions.
 This practice simplifies the API for :py:class:`~pvlib.pvsystem.PVSystem`
 and :py:class:`~pvlib.pvsystem.Array` methods by eliminating the need to specify

docs/sphinx/source/whatsnew/v0.9.0.rst

@@ -202,7 +202,8 @@ Documentation
   and to make the procedural and OO results match exactly. (:issue:`1116`, :pull:`1144`)
 * Add a gallery example showing how to appropriately use interval-averaged
   weather data for modeling. (:pull:`1152`)
-* Update documentation links in :py:func:`pvlib.iotools.get_psm3`
+* Update documentation links in :py:func:`pvlib.iotools.get_psm3` (:pull:`1169`)
+* Use ``Mount`` classes in ``introtutorial`` and ``pvsystem`` docs pages (:pull:`1267`)
 * Clarified how statistics are calculated for :py:func:`pvlib.clearsky.detect_clearsky`
   (:issue:`1070`, :pull:`1243`)