spatialEco (version 0.1-7)

raster.mds: Raster multidimensional scaling (MDS)

Description

Multidimensional scaling of raster values within an N x N focal window

Usage

raster.mds(r, s = 5, window.median = FALSE, ...)

Arguments

r

Raster layer

s

Window size (may be a vector of 1 or 2) of n x n dimension. If only one value provided then a square matrix (window) will be used.

window.median

(TRUE/FALSE) Return the median of the MDS matrix values. If FALSE then the center value of the matrix is returned and not the median of the matrix

...

Additional arguments passed to raster::focal (if you want a file written to disk use filename = "" argument)

Value

A raster class object or raster written to disk

References

Quinn, G.P., & M.J. Keough (2002) Experimental design and data analysis for biologists. Cambridge University Press. Ch. 18. Multidimensional scaling and cluster analysis.

Examples

 library(raster)
 r <- raster(system.file("external/rlogo.grd", package="raster")) 
   r <- r / cellStats(r, "max")
 
 diss <- raster.mds(r)
 diss.med <- raster.mds(r, window.median = TRUE)
   par(mfrow=c(2,2))
   plot(r)
     title("R logo band-1")
   plot( focal(r, w = matrix(1, nrow=5, ncol=5), fun = var) )
     title("Variance")		 
     plot(diss)
       title("MDS")
     plot(diss.med)
       title("Median MDS")