# width.SJ

0th

Percentile

Uses the method of Sheather & Jones (1991) to select the bandwidth of a Gaussian kernel density estimator.

Keywords
dplot
##### Usage
width.SJ(x, nb = 1000, lower, upper, method = c("ste", "dpi"))
##### Arguments
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" ("solve-the-equation") or "dpi" ("direct plug-in").

a bandwidth.

##### Note

A faster version for large n (thousands) is available in R $\ge$ 3.4.0 as part of bw.SJ: quadruple its value for comparability with this version.

##### References

Sheather, S. J. and Jones, M. C. (1991) A reliable data-based 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.

ucv, bcv, density
library(MASS) width.SJ(geyser$duration, method = "dpi") width.SJ(geyser$duration) width.SJ(galaxies, method = "dpi") width.SJ(galaxies)