gstat (version 0.9-22)

plot.gstatVariogram: Plot a Sample Variogram

Description

Creates a variogram plot

Usage

plot.gstatVariogram(x, model = NULL, ylim, xlim, xlab = "distance", 
	ylab = "semivariance", multipanel = TRUE, plot.numbers = FALSE, 
	scales, ids = x$id, group.id = TRUE, skip, layout, ...)
plot.variogramMap(x, np = FALSE, skip, threshold, ...)

Arguments

x

object of class "gstatVariogram", obtained from the function variogram, possibly containing directional or cross variograms

model

in case of a single variogram: a variogram model, as obtained from vgm or fit.variogram, to be drawn as a line in the variogram plot; in case of a set of variograms and cross vari

ylim

numeric vector of length 2, limits of the y-axis

xlim

numeric vector of length 2, limits of the x-axis

xlab

x-axis label

ylab

y-axis label

multipanel

logical; if TRUE, directional variograms are plotted in different panels, if FALSE, directional variograms are plotted in the same graph, using color, colored lines and symbols to distinguish them

plot.numbers

logical; if TRUE, plot number of point pairs next to each plotted semivariance symbol

scales

optional argument that will be passed to xyplot in case of the plotting of variograms and cross variograms; use the value list(relation = "same") if y-axes need to share scales

ids

ids of the data variables and variable pairs

group.id

logical; control for directional multivariate variograms: if TRUE, panels divide direction and colors indicate variables (ids), if FALSE panels divide variables/variable pairs and colors indicate direction

skip

logical; can be used to arrange panels, see xyplot

layout

integer vector; can be used to set panel layout: c(ncol,nrow)

np

logical; if TRUE, plot number of point pairs, if FALSE plot semivariances

threshold

semivariogram map values based on fewer point pairs than threshold will not be plotted

...

any arguments that will be passed to the panel plotting functions (such as auto.key in examples below)

Value

• returns (or plots) the variogram plot

References

http://www.gstat.org

See Also

variogram, fit.variogram, vgm variogram.line,

Examples

data(meuse)
vgm1 <- variogram(log(zinc)~1, ~x+y, meuse)
plot(vgm1)
model.1 <- fit.variogram(vgm1,vgm(1,"Sph",300,1))
plot(vgm1, model=model.1)
plot(vgm1, plot.numbers = TRUE, pch = "+")
vgm2 <- variogram(log(zinc)~1, ~x+y, meuse, alpha=c(0,45,90,135))
plot(vgm2)
# the following demonstrates plotting of directional models:
model.2 <- vgm(.59,"Sph",926,.06,anis=c(0,0.3))
plot(vgm2, model=model.2)
 
g = gstat(id="zinc < 200", form=I(zinc<200)~1,loc=~x+y,data=meuse)
g = gstat(g, id="zinc < 400", form=I(zinc<400)~1,loc=~x+y,data=meuse)
g = gstat(g, id="zinc < 800", form=I(zinc<800)~1,loc=~x+y,data=meuse)
# calculate multivariable, directional variogram:
v = variogram(g, alpha=c(0,45,90,135))
plot(v, group.id = FALSE, auto.key = TRUE) # id and id pairs panels
plot(v, group.id = TRUE, auto.key = TRUE)  # direction panels

if (require(sp)) {
  plot(variogram(g, cutoff=1000, width=100, map=TRUE),
  	main = "(cross) semivariance maps")
  plot(variogram(g, cutoff=1000, width=100, map=TRUE), np=TRUE,
  	main = "number of point pairs")
}