Prepare the solar position, irradiance and weather inputs to the model, starting with plane-of-array irradiance.

Parameters:data (DataFrame) – Contains plane-of-array irradiance data. Required column names include 'poa_global', 'poa_direct' and 'poa_diffuse'. Columns with weather-related data are ssigned to the weather attribute. If columns for 'temp_air' and 'wind_speed' are not provided, air temperature of 20 C and wind speed of 0 m/s are assumed.


Assigns attributes: weather, total_irrad, solar_position, airmass, aoi.