Ipython notebook tutorial for irradiance is out of date?

[garciaev]

Hi -

It looks like the Ipython notebook tutorial irradiance.pynb has code to compute the ineichen model as follows:

irrad_data = pvlib.clearsky.ineichen(times, tus.latitude, tus.longitude, tus.altitude)
irrad_data.plot()

Which gives an error:

Traceback (most recent call last):
File "compute_ghi.py", line 41, in
tus.longitude, tus.altitude)
File "//anaconda/lib/python2.7/site-packages/pvlib/clearsky.py", line 113, in ineichen
cos_zenith = np.maximum(tools.cosd(apparent_zenith), 0)
File "//anaconda/lib/python2.7/site-packages/pvlib/tools.py", line 26, in cosd
res = np.cos(np.radians(angle))
TypeError: ufunc 'radians' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''

It looks like the clearsky.ineichen takes solar zenith angle as the first argument? However, this code does reproduce what is seen in the middle figure of out[11] of irradiance.pynb for linke turbidity = 2.0, all other code being the same:

irrad_data = tus.get_clearsky(times, model='ineichen', linke_turbidity=2)

[wholmgren]

The API changed in version 0.4. I thought this tutorial worked with the new version of pvlib (it does have a note at the top saying that it should) but I guess I missed something or forgot to commit a change.

There's a very similar example in the documentation that does work...

http://pvlib-python.readthedocs.io/en/latest/clearsky.html#examples

Do you want to make a pull request with the change? You'll want to use the notebook's "Restart and run all" command until it works through the end.