R: Plot a Variogram Object

plot.Variogram {nlme}

R Documentation

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 class 'Variogram'
plot(x, smooth, showModel, sigma, span, xlab,
     ylab, type, ylim, grid, ...)

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.

Value

an xyplot Trellis plot.

Author(s)

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

Examples

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

[Package nlme version 3.1-164 Index]