ENH: add methods and tests for a explicit IV curve calculation of single-diode model

.gitignore

@@ -1,4 +1,5 @@
 # Byte-compiled / optimized / DLL files
+.pytest_cache/
 __pycache__/
 *.py[cod]
 

docs/sphinx/source/api.rst

@@ -65,7 +65,6 @@ algorithm.
 
    spa
 
-
 Correlations and analytical expressions for low precision solar position
 calculations.
 
@@ -80,6 +79,7 @@ calculations.
    solarposition.equation_of_time_pvcdrom
    solarposition.hour_angle
 
+
 Clear sky
 =========
 
@@ -205,6 +205,23 @@ Functions relevant for the single diode model.
    pvsystem.i_from_v
    pvsystem.singlediode
    pvsystem.v_from_i
+   pvsystem.mpp
+   pvsystem.estimate_voc
+   pvsystem.bishop88
+
+Low-level functions to support :func:`pvlib.pvsystem.bishop88`. *Note*:
+:func:`pvlib.singlediode_methods.bishop88` and
+:func:`pvlib.singlediode_methods.estimate_voc` are also imported into the
+``pvlib.pvsystem`` module.
+
+.. autosummary::
+   :toctree: generated/
+
+   singlediode_methods.estimate_voc
+   singlediode_methods.bishop88
+   singlediode_methods.bishop88_i_from_v
+   singlediode_methods.bishop88_v_from_i
+   singlediode_methods.bishop88_mpp
 
 SAPM model
 ----------
@@ -231,7 +248,6 @@ PVWatts model
    pvsystem.pvwatts_ac
    pvsystem.pvwatts_losses
 
-
 Other
 -----
 

docs/sphinx/source/whatsnew/v0.6.0.rst

@@ -11,9 +11,37 @@ API Changes
 
 Enhancements
 ~~~~~~~~~~~~
-* Add sea surface albedo in irradiance.py (:issue:`458`)
-* Implement first_solar_spectral_loss in modelchain.py (:issue:`359`)
-* Clarify arguments Egref and dEgdT for calcparams_desoto (:issue:`462`)
+* Add sea surface albedo in ``irradiance.py`` (:issue:`458`)
+* Implement :meth:`~pvlib.modelchain.ModelChain.first_solar_spectral_loss`
+  in ``modelchain.py`` (:issue:`359`)
+* Clarify arguments ``Egref`` and ``dEgdT`` for
+  :func:`~pvlib.pvsystem.calcparams_desoto` (:issue:`462`)
+* Implement a reliable "gold" implementation of the single diode model (SDM)
+  using a bisection method (Brent, 1973) bounded by points known to include the
+  full forward-bias 1st quadrant IV-curve. Also implement a "fast" method using
+  the Newton-Raphson method that is not bounded, but should be safe for well
+  behaved IV-curves. (:issue:`408`)
+* Implement :func:`~pvlib.pvsystem.bishop88` for explicit calculation of
+  arbitrary IV curve points using diode voltage instead of cell voltage. This
+  method is called for ``ivcurve_pnts`` in :func:`~pvlib.pvsystem.singlediode`
+  if the method is either ``'newton'`` or ``'brentq'``, but the IV curve points
+  will be log spaced instead of linear.
+* Implement :func:`~pvlib.pvsystem.estimate_voc` to estimate open circuit
+  voltage by assuming :math:`R_{sh} \to \infty` and :math:`R_s=0` as an upper
+  bound in bisection method for :func:`~pvlib.pvsystem.singlediode`.
+* Combine existing :func:`~pvlib.pvsystem.singlediode` method using Lambert-W
+  with the two new implementations to form a wrapper, that takes an additional
+  ``method`` argument ``('lambertw', 'newton', 'brentq')`` that defaults to a
+  Lambert-W solution. Selecting either "brentq" or "newton" as the method uses
+  ``bishop88`` with the corresponding search method. (:issue:`410`)
+* Add :func:`~pvlib.pvsystem.mpp` method to compute the max power point using
+  the new "brentq" bounded bisection method.
+* Add new module ``pvlib.singlediode_methods`` which contains low-level
+  functions to support implementing ``bishop88`` and various other methods like
+  ``bishop88_i_from_v``, ``bishop88_v_from_i``, and ``bishop88_mpp``. *Note*:
+  :func:`pvlib.singlediode_methods.bishop88` and
+  :func:`pvlib.singlediode_methods.estimate_voc` are also imported into the
+  ``pvlib.pvsystem`` module.
 
 
 Bug fixes
@@ -48,5 +76,6 @@ Contributors
 * Will Holmgren
 * Yu Cao
 * Cliff Hansen
+* Mark Mikofski
 * Alan Mathew