Add GTI DIRINT model (#400)

* implement gtidirint without iteration

* add option to skip aoi > 90

* make gti dirint gte 90 function private

* add some gti_dirint tests

* implement vectorized iterative solution. fix gt 90 error

* use azimuth in gt 90 function

* fix some issues near 90 deg

* remove unnecessary comment

* add kt option to disc, dirint to fix gte 90 dni issue

* update whatsnew, add to api.rst

* move to 0.5.2 whatsnew

* add gti_dirint tutorial

* move changes to 0.6.0 whatsnew

* update parameters

* fix 0.5.2 whatsnew

* rework max_iterations logic

* flake8

* update tutorial

* api change in whatsnew

* clean up whatsnew

* update to new api. fix parameters

* update notebook [skip ci]

* refactor

* more refactoring

* refactor disc and dirint

* clean up

* update tutorial

* add stubs. use zeros. more clean up

* review comments

* rerun on master

* some broken tests

* update parameters, whatsnew. [skip ci]

* update tests

* update documentation

* ignore .vscode

* limit clearness index in disc dirint dirindex

* fix bad change

* update tutorial

* remove tutorial

* maybe fix failing py27 test

* doc clean up

* update doi

Author: wholmgren

.gitignore

@@ -38,7 +38,8 @@ pvlib/spa_c_files/spa.h
 pvlib/spa_c_files/spa_tester.c
 
 # generated documentation
-# pvlib/sphinx/Docs/build/
+docs/sphinx/source/generated
+docs/sphinx/source/savefig
 
 # Installer logs
 pip-log.txt
@@ -62,6 +63,7 @@ coverage.xml
 .idea/
 *.sublime-project
 *.sublime-workspace
+.vscode
 
 # Rope
 .ropeproject

docs/sphinx/source/api.rst

@@ -167,6 +167,16 @@ DNI estimation models
    irradiance.dirindex
    irradiance.erbs
    irradiance.liujordan
+   irradiance.gti_dirint
+
+Clearness index models
+----------------------
+
+.. autosummary::
+   :toctree: generated/
+
+   irradiance.clearness_index
+   irradiance.clearness_index_zenith_independent
 
 
 PV Modeling

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

@@ -49,6 +49,8 @@ API Changes
   enhancement factor can yield unphysical results, especially for latitudes
   closer to the poles and especially in the winter months. It may yield
   improved results under other conditions. (:issue:`435`)
+* Add min_cos_zenith, max_zenith keyword arguments to disc, dirint, and
+  dirindex functions. (:issue:`311`, :issue:`396`)
 
 
 Enhancements
@@ -96,6 +98,9 @@ Enhancements
 * Improve performance of Location.get_airmass. Most noticeable when
   solar position is supplied, time index length is less than 10000, and
   method is looped over. (:issue:`502`)
+* Add irradiance.gti_dirint function. (:issue:`396`)
+* Add irradiance.clearness_index function. (:issue:`396`)
+* Add irradiance.clearness_index_zenith_independent function. (:issue:`396`)
 
 
 Bug fixes
@@ -118,6 +123,7 @@ Bug fixes
   Hay-Davies diffuse sky algorithms. (:issue:`432`)
 * Fix argument order of longitude and latitude when querying weather forecasts
   by lonlat bounding box (:issue:`521`)
+* Fix issue with unbounded clearness index calculation in disc. (:issue:`540`)
 * Limit pvwatts_ac results to be greater than or equal to 0. (:issue:`541`)