Principal Coordinates Analysis
Principal coordinates analysis is an eigenanalysis of distance or metric dissimilarity matrices.
pco(dis, k=2)
pco is simply a wrapper for the cmdscale function
of Venebles and Ripley to make plotting of the function similar to
other LabDSV functions
An object of class ‘pco’ with components:
points |
the coordinates of samples on eigenvectors |
Principal Coordinates Analysis was pioneered by Gower (1966) as an alternative to PCA better suited to ecological datasets.
of the ‘cmdscale’ function: Venebles and Ripley
of the wrapper function David W. Roberts droberts@montana.edu http://ecology.msu.montana.edu/droberts/droberts.html
Gower, J.C. (1966) Some distance properties of latent root and vector methods used in multivariate analysis. Biometrika 53:325-328.
data(bryceveg) # returns a vegetation data.frame
dis.bc <- dsvdis(bryceveg,'bray/curtis')
# returns an object of class dist'
veg.pco <- pco(dis.bc,k=4) # returns first 4 dimensions
plot(veg.pco)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.