Functions for Drawing Ellipses and Ellipse-Like Confidence
Regions
Duncan Murdoch <murdoch@stats.uwo.ca> and E. D. Chow 
    (porting to R by Jesus M. Frias Celayeta <iosu@bureau.ucc.ie>)
Contains various routines for drawing
    ellipses and ellipse-like confidence regions, implementing the plots
    described in Murdoch and Chow (1996), A graphical display of large
    correlation matrices, The American Statistician 50, 178-180. There are
    also routines implementing the profile plots described in Bates and
    Watts (1988), Nonlinear Regression Analysis and its Applications.