plot.Variogram: Plot a Variogram Object

Description

an xyplot of the semi-variogram versus the distances is produced. If smooth = TRUE, a loess smoother is added to the plot. If showModel = TRUE and x includes an "modelVariog" attribute, the corresponding semi-variogram is added to the plot.

Usage

# S3 method for Variogram
plot(x, smooth, showModel, sigma, span, xlab,
     ylab, type, ylim, grid, ...)

Value

an xyplot Trellis plot.

Arguments

x: an object inheriting from class "Variogram", consisting of a data frame with two columns named variog and dist, representing the semi-variogram values and the corresponding distances.
smooth: an optional logical value controlling whether a loess smoother should be added to the plot. Defaults to TRUE, when showModel is FALSE.
showModel: an optional logical value controlling whether the semi-variogram corresponding to an "modelVariog" attribute of x, if any is present, should be added to the plot. Defaults to TRUE, when the "modelVariog" attribute is present.
sigma: an optional numeric value used as the height of a horizontal line displayed in the plot. Can be used to represent the process standard deviation. Default is NULL, implying that no horizontal line is drawn.
span: an optional numeric value with the smoothing parameter for the loess fit. Default is 0.6.
xlab,ylab: optional character strings with the x- and y-axis labels. Default respectively to "Distance" and "SemiVariogram".
type: an optional character indicating the type of plot. Defaults to "p".
ylim: an optional numeric vector with the limits for the y-axis. Defaults to c(0, max(x$variog)).
grid: an optional logical value indicating whether a grid should be added to plot. Default is FALSE.
...: optional arguments passed to the Trellis xyplot function.

Author

José Pinheiro and Douglas Bates bates@stat.wisc.edu

Examples

Run this code

fm1 <- lme(follicles ~ sin(2*pi*Time) + cos(2*pi*Time), Ovary)
plot(Variogram(fm1, form = ~ Time | Mare, maxDist = 0.7))