RLOWESS function applies an iterative smoothing program on a Geo Time Series™ or a LIST of Geo Time Series™, which is done via locally weighted regression, and is robust to outliers.
Cleveland, W. S. (1979) Robust locally weighted regression and smoothing scatter plots. J. American Statistical Association 74, 829–836.
Cleveland, W. S. (1981) LOWESS: A program for smoothing scatter plots by robust locally weighted regression. The American Statistician 35, 54.