History of the `sm' library by Adrian W. Bowman & Adelchi Azzalini -------------------------------------- September 1997: version 1 of the library for S-plus is released. February 1999: porting to R by Brian Ripley July 2000: porting to XLisp-Stat by Luca Scrucca November 2000: version 2 for S-plus is released. The main differences from version 1 are: - datasets of arbitrary size can be handled, using binning operations; this feature operates on the main functions: sm.density, sm.regression, sm.ancova, sm.binomial, sm.poisson, but not for all functions (for instance it does not operate for time series related functions); - missing data are allowed, by simply removing them, together with associated variates of the same case; - sm.options is introduced, providing an improved mechanism for parameter passing (but this is essentially trasparent to the user); - the code of GLM-type functions has been modified somewhat; sm.logit has been renamed to sm.binomial, and similarly sm.logit.bootstrap to sm.binomial.bootstrap; - some of the associated scripts have been modified slightly; - some other minor changes (e.g. the function type() has been removed). September 2005: version 2.1 for R is released. - more extensive methods of selecting smoothing parameters have been implemented, and in a more systematic manner, for density estimation and regression; the methods for regression now include one based on AIC, proposed by Hurvich, Simonoff and Tsai; - the operation of the code has been streamlined; - some other minor changes have been implemented. September 2007: version 2.2 for R is released. - rotatable rgl plots can be produced by sm.density and sm.regression. - rpanel interactive controls are available in sm.density and sm.regression. - other minor changes.