R: Image or Perspective Plot with Kriging Results

image.kriging {geoR} | R Documentation

## Image or Perspective Plot with Kriging Results

### Description

Plots image or perspective plots with results of the kriging calculations.

### Usage

    ## S3 method for class 'kriging'
    image(x, locations, borders, values = x$predict,
                  coords.data, x.leg, y.leg, ...)
    ## S3 method for class 'kriging'
    contour(x, locations, borders, values = x$predict,
                  coords.data, filled=FALSE, ...)
    ## S3 method for class 'kriging'
    persp(x, locations, borders, values = x$predict, ...)

### Arguments

`x` | an object of the class `kriging`, typically with the output of the functions `krige.conv` or `ksline`.
`locations` | an n x 2 matrix with the coordinates of the prediction locations, which should define a regular grid in order to be plotted by `image` or `persp`. By default does not need to be provided and evaluates the attribute "prediction.locations" from the input object.
`borders` | an n x 2 matrix with the coordinates defining the borders of a region inside the grid defined by `locations`. Elements in the argument `values` are assigned to locations internal to the borders and `NA`'s to the external ones.
`values` | a vector with values to be plotted. Defaults to `obj$predict`.
`coords.data` | optional. If an n x 2 matrix with the data coordinates is provided, points indicating the data locations are included in the plot.
`x.leg, y.leg` | limits for the legend in the horizontal and vertical directions.
`filled` | logical. If `FALSE` the function `contour` is used otherwise `filled.contour`. Defaults to `FALSE`.
`...` | further arguments to be passed to the functions `image`, `contour`, `filled.contour`, `persp` or `legend.krige`. For instance, the argument `zlim` can be used to set the the minimum and maximum ‘z’ values for which colors should be plotted. See documentation for those function for possible arguments.

### Details

`plot1d` and `prepare.graph.kriging` are auxiliary functions called by the others.

### Value

An image or perspective plot is produced o the current graphics device. No values are returned.

### Author(s)

Paulo J. Ribeiro Jr. paulojus@leg.ufpr.br,
Peter J. Diggle p.diggle@lancaster.ac.uk.

### References

Further information on the package geoR can be found at:
http://www.leg.ufpr.br/geoR.

### See Also

`krige.conv` and `ksline` for kriging calculations. Documentation for `image`, `contour`, `filled.contour` and `persp` contain basic information on the plotting functions.

### Examples

    loci <- expand.grid(seq(0,1,l=51), seq(0,1,l=51))
    kc <- krige.conv(s100, loc=loci,
                     krige=krige.control(cov.pars=c(1, .25)))
    image(kc)
    contour(kc)
    image(kc)
    contour(kc, add=TRUE, nlev=21)
    persp(kc, theta=20, phi=20)
    contour(kc, filled=TRUE)
    contour(kc, filled=TRUE, color=terrain.colors)
    contour(kc, filled=TRUE, col=gray(seq(1,0,l=21)))
    # adding data locations
    image(kc, coords.data=s100$coords)
    contour(kc,filled=TRUE,coords.data=s100$coords,color=terrain.colors)
    #
    # now dealing with borders
    #
    bor <- matrix(c(.4,.1,.3,.9,.9,.7,.9,.7,.3,.2,.5,.8),
                  ncol=2)
    # plotting just inside borders
    image(kc, borders=bor)
    contour(kc, borders=bor)
    image(kc, borders=bor)
    contour(kc, borders=bor, add=TRUE)
    contour(kc, borders=bor, filled=TRUE, color=terrain.colors)
    # kriging just inside borders
    kc1 <- krige.conv(s100, loc=loci,
                     krige=krige.control(cov.pars=c(1, .25)),
                     borders=bor)
    image(kc1)
    contour(kc1)
    # avoiding the borders
    image(kc1, borders=NULL)
    contour(kc1, borders=NULL)

    op <- par(no.readonly = TRUE)
    par(mfrow=c(1,2), mar=c(3,3,0,0), mgp=c(1.5, .8,0))
    image(kc)
    image(kc, val=sqrt(kc$krige.var))

    # different ways to add the legends and pass arguments:
    image(kc, ylim=c(-0.2, 1), x.leg=c(0,1), y.leg=c(-0.2, -0.1))
    image(kc, val=kc$krige.var, ylim=c(-0.2, 1))
    legend.krige(y.leg=c(-0.2,-0.1), x.leg=c(0,1), val=sqrt(kc$krige.var))

    image(kc, ylim=c(-0.2, 1), x.leg=c(0,1), y.leg=c(-0.2, -0.1), cex=1.5)
    image(kc, ylim=c(-0.2, 1), x.leg=c(0,1), y.leg=c(-0.2, -0.1), offset.leg=0.5)

    image(kc, xlim=c(0, 1.2))
    legend.krige(x.leg=c(1.05,1.1), y.leg=c(0,1), kc$pred, vert=TRUE)
    image(kc, xlim=c(0, 1.2))
    legend.krige(x.leg=c(1.05,1.1), y.leg=c(0,1),kc$pred, vert=TRUE, off=1.5, cex=1.5)

    par(op)

[Package geoR version 1.7-5.2 Index]