This is an R port of Trevor Hastie's principal.curve package which can
be found in the statlib archive.

Changes from original:

	default smoother in "principal.curve" is "lowess", because
	"smooth.spline" is yet not implemented in R.

	replaced missing ylim.scale by own function

	changes in "periodic lowess" and changes in the call of
	"periodic.lowess" in the subroutine "bias.correct.curve" 

	All changes are marked by a comment starting with AW. 

The latest version of this package can always be downloaded from any
CRAN mirror. The CRAN master site can be found at

        http://www.ci.tuwien.ac.at/R
        ftp://ftp.ci.tuwien.ac.at/pub/R


************************************************************************
*                          Andreas Weingessel                          *
************************************************************************
* Institut fr Statistik      *                Tel: (+43 1) 58801 4541 *
* Technische Universitt Wien *                Fax: (+43 1)  504 14 98 *
* Wiedner Hauptstr. 8-10/1071 *     Andreas.Weingessel@ci.tuwien.ac.at *
* A-1040 Wien, Austria        * http://www.ci.tuwien.ac.at/~weingessel *
************************************************************************

The address of Trevor Hastie is (according to the information provided
in the statlib package):

Trevor Hastie           trevor@research.att.com
1-908-582-5647          (FAX) 1-908-582-3340
rm 2C-261 AT&T Bell Labs, Murray Hill, NJ 07974

