ordcomp {labdsv}

Ordination to Dissimilarity Comparison

Description

Plots the distribution of pair-wise distances of all points in an ordination over the distances in the dissimilarity or distance matrix the ordination was calculated from. Prints the correlation between the two on the graph.

Usage

ordcomp(x,dis,dim,xlab="Computed Distance",
        ylab="Ordination Distance",title="",pch=1)

Arguments

x

an ordination object of class ‘dsvord’ from pca, pco, nmds, fso or
ordiplot

dis

an object of class dist

dim

the number of dimensions in the ordination to use (default=all)

xlab

the X axis label for the graph

ylab

the Y axis label for the graph

title

a title for the plot

pch

the symbol to plot

Value

A plot is created on the current graphics device. Returns the (invisible) correlation.

Note

Ordinations are low dimensional representations of multidimensional spaces. This function attempts to portray how well the low dimensional solution approximates the full dimensional space.

Author(s)

David W. Roberts [e-mail]

Examples

data(bryceveg) # produces a vegetation data.frame
dis.bc <- dsvdis(bryceveg,'bray/curtis') # creates a Bray/Curtis 
                                         # dissimilarity matrix
pco.bc <- pco(dis.bc,2) # produces a two-dimensional Principal 
                        # Coordinates Ordination object
ordcomp(pco.bc,dis.bc)