farms.utilities.ti_to_radius

farms.utilities.ti_to_radius(time_index, n_cols=1)[source]

Calculates Earth-Sun Radius Vector.

Reference: http://www.nrel.gov/docs/fy08osti/34302.pdf

Parameters:

  • time_index (pandas.core.indexes.datetimes.DatetimeIndex) – NSRDB time series. Can extract from h5 as follows: time_index = pd.to_datetime(h5[‘time_index’][…].astype(str))

  • n_cols (int) – Number of columns to output. The radius vertical 1D array will be copied this number of times horizontally (np.tile).

Returns:

radius (np.array) – Array of radius values matching the time index. Shape is (len(time_index), n_cols).