is.euclid {ade4} | R Documentation |
Confirmation of the Euclidean nature of a distance matrix by the Gower's theorem.
is.euclid is used in summary.dist.
mat2dist and dist2mat are local copies of as.dist and as.matrix.dist of mva.
is.euclid(distmat, plot = FALSE, print = FALSE, tol = 1e-07) summary.dist(object, ...)
distmat |
an object of class 'dist' |
plot |
a logical value indicating whether the eigenvalues bar plot of the matrix of the term -1/2 dijē centred by rows and columns should be diplayed |
print |
a logical value indicating whether the eigenvalues of the matrix of the term -1/2 dijē centred by rows and columns should be printed |
tol |
a tolerance threshold : an eigenvalue is considered positive if it is larger than -tol*lambda1 where lambda1 is the largest eigenvalue. |
object |
an object of class 'dist' |
... |
further arguments passed to or from other methods |
returns a logical value indicating if all the eigenvalues are positive or equal to zero
Gower, J.C. and Legendre, P. (1986) Metric and Euclidean properties of dissimilarity coefficients. Journal of Classification, 3, 548.
w <- matrix(runif(10000), 100, 100) w <- dist(w) summary(w) is.euclid (w) # TRUE w <- quasieuclid(w) # no correction need in: quasieuclid(w) w <- lingoes(w) # no correction need in: lingoes(w) w <- cailliez(w) # no correction need in: cailliez(w) rm(w)