vcv.phylo: Phylogenetic Variance-covariance or Correlation Matrix
Description
This function computes the expected variances and covariances of a
continuous phenotype assuming it evolves under a given model
(currently only the model of Brownian motion is available).
Usage
vcv.phylo(phy, model = "Brownian", cor = FALSE)
Arguments
phy
an object of class "phylo".
model
a character giving the model used to compute the
variances and covariances of the phynotype; by default
"Brownian". Currently only Brownian is available.
cor
a logical indicating whether the correlation matrix should
be returned (TRUE); by default the variance-covariance matrix
is returned (FALSE).
Value
a numeric matrix with the names of the tips (as given by the tip.label
of the argument `phy') as colnames and rownames.
References
Garland, T. Jr. and Ives, A. R. (2000) Using the past to predict the
present: confidence intervals for regression equations in phylogenetic
comparative methods. American Naturalist, 155, 346--364.