width.SJ {MASS}  R Documentation 
Uses the method of Sheather & Jones (1991) to select the bandwidth of a Gaussian kernel density estimator.
width.SJ(x, nb = 1000, lower, upper, method = c("ste", "dpi"))
x 
a numeric vector 
nb 
number of bins to use. 
upper, lower 
range over which to search for solution if method = "ste" .

method 
Either "ste" ("solvetheequation") or "dpi"
("direct plugin").

a bandwidth.
Sheather, S. J. and Jones, M. C. (1991) A reliable databased bandwidth selection method for kernel density estimation. Journal of the Royal Statistical Society series B 53, 683–690.
Scott, D. W. (1992) Multivariate Density Estimation: Theory, Practice, and Visualization. Wiley.
Wand, M. P. and Jones, M. C. (1995) Kernel Smoothing. Chapman & Hall.
attach(geyser) width.SJ(duration, method = "dpi") width.SJ(duration) detach() width.SJ(galaxies, method = "dpi") width.SJ(galaxies)