raster.mds: Raster multidimensional scaling (MDS)

In spatialEco: Spatial Analysis and Modelling Utilities

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	A terra SpatRaster class object
s	Window size (may be a vector of 1 or 2) of n x n dimension.
window.median	(FALSE/TRUE) Return the median of the MDS matrix values.
...	Additional arguments passed to terra::focal

Details

An MDS focal function. If only one value provided for s, then a square matrix (window) will be used. If window.median = FALSE then the center value of the matrix is returned and not the median of the matrix

Value

A terra SpatRaster class object

Author(s)

Jeffrey S. Evans <[e-mail]>

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(terra)
 r <- rast(system.file("ex/elev.tif", package="terra"))
   r <- r[[1]] / max(global(r, "max", na.rm=TRUE)[,1])
 
 diss <- raster.mds(r)
 diss.med <- raster.mds(r, window.median = TRUE)

opar <- par(no.readonly=TRUE)
   par(mfrow=c(2,2))
   plot(r)
     title("Elevation")
   plot( focal(r, w = matrix(1, nrow=5, ncol=5), fun = var) )
     title("Variance")		 
     plot(diss)
       title("MDS")
     plot(diss.med)
       title("Median MDS")
par(opar)

spatialEco documentation built on Nov. 18, 2023, 1:13 a.m.