If zeropad is non-zero, the extra samples used to pad each end of the data streams are set to 0 prior to filtering within the initial cleaning, and apodization is used to slowly roll-off the ends of the time series to 0 (see parameter "apod" ). If zeropad is zero, a cubic polynomial is used to interpolate smoothly between the end of the time series and the beginning of the time series, ensuring continuity in both the value and first derivative. In both cases, the purpose is to remove sharp edges that may cause ringing in the FFT filtering steps. [0]

SC2CLEAN, MAKEMAP, CALCQU