pedometrics (version 0.4-1)

plotESDA: Plots for exploratory spatial data analysis (ESDA)

Description

This function creates four plots for exploratory spatial data analysis (ESDA): histogram + density plot, bubble plot, variogram plot, and variogram map.

Usage

plotESDA(z, lat, lon, cutoff, width = c(cutoff/20))

Arguments

z

Vector of numeric values of the variable for with ESDA plots should be created.

lat

Vector of numeric values containing the y coordinate (latitude) of the point locations where the z variable was observed.

lon

Vector of numeric values containing the x coordinate (longitude) of the point locations where the z variable was observed.

cutoff

Integer value defining the spatial separation distance up to which point pairs are included in semivariance estimates. Defaults to the length of the diagonal of the box spanning the data divided by three.

width

Integer value specifying the width of subsequent distance intervals into which data point pairs are grouped for semivariance estimates. Defaults to width = cutoff / 20.

Value

• Four plots: histogram and density plot, bubble plot, empirical variogram, and variogram map.

TODO

The next version should include an option to pass data using an object of class "SpatialPointsDataFrame".

Details

The user should visit the help pages of variogram, plotHD, bubble and spplot to obtain more details about the main functions used to built plotESDA.

References

Cressie, N.A.C. (1993) Statistics for Spatial Data. New York: John Wiley & Sons, p.900, 1993.

Pebesma, E.J. (2004) Multivariable geostatistics in S: the gstat package. Computers & Geosciences, 30:683-691, 2004.

Webster, R. & Oliver, M.A. Geostatistics for environmental scientists. Chichester: John Wiley & Sons, p.315, 2007.

See Also

variogram, plotHD, bubble, spplot.

Examples

# require(gstat)
# data(meuse)
# plotESDA(z = meuse$zinc, lat = meuse$y, lon = meuse$x)