Plot and Identify Data Pairs on Sample Variogram Cloud

Plot a sample variogram cloud, possibly with identification of individual point pairs

Usage

# S3 method for class 'variogramCloud'
plot(x, identify = FALSE, digitize = FALSE, xlim, ylim, xlab, ylab, 
  keep = FALSE, ...)

Arguments

x: object of class variogramCloud
identify: logical; if TRUE, the plot allows identification of a series of individual point pairs that correspond to individual variogram cloud points (use left mouse button to select; right mouse button ends)
digitize: logical; if TRUE, select point pairs by digitizing a region with the mouse (left mouse button adds a point, right mouse button ends)
xlim: limits of x-axis
ylim: limits of y-axis
xlab: x axis label
ylab: y axis label
keep: logical; if TRUE and identify is TRUE, the labels identified and their position are kept and glued to object x, which is returned. Subsequent calls to plot this object will now have the labels shown, e.g. to plot to hardcopy
...: parameters that are passed through to plot.gstatVariogram (in case of identify = FALSE) or to plot (in case of identify = TRUE)

Value

If identify or digitize is TRUE, a data frame of class pointPairs with in its rows the point pairs identified (pairs of row numbers in the original data set); if identify is F, a plot of the variogram cloud, which uses plot.gstatVariogram

If in addition to identify, keep is also TRUE, an object of class variogramCloud is returned, having attached to it attributes "sel" and "text", which will be used in subsequent calls to plot.variogramCloud with identify set to FALSE, to plot the text previously identified.

If in addition to digitize, keep is also TRUE, an object of class variogramCloud is returned, having attached to it attribute "poly", which will be used in subsequent calls to plot.variogramCloud with digitize set to FALSE, to plot the digitized line.

In both of the keep = TRUE cases, the attribute ppairs of class pointPairs is present, containing the point pairs identified.

References

http://www.gstat.org/

Author

Edzer Pebesma

Examples

library(sp)
data(meuse)
coordinates(meuse) = ~x+y
plot(variogram(log(zinc)~1, meuse, cloud=TRUE))

## commands that require interaction:
# x <- variogram(log(zinc)~1, loc=~x+y, data=meuse, cloud=TRUE)
# plot(plot(x, identify = TRUE), meuse)
# plot(plot(x, digitize = TRUE), meuse)