Pagel's ``lambda'' Correlation Structure
The correlation structure from the present model is derived from the Brownian motion model by multiplying the off-diagonal elements (i.e., the covariances) by $\lambda$. The variances are thus the same than for a Brownian motion model.
corPagel(value, phy, form = ~1, fixed = FALSE) ## S3 method for class 'corPagel': corMatrix(object, covariate = getCovariate(object), corr = TRUE, ...) ## S3 method for class 'corPagel': coef(object, unconstrained = TRUE, \dots)
an object of class
"corPagel", the coefficients from an object
of this class, or the correlation matrix of an initialized object of
this class. In most situations, only
corPagel will be called
by the user.
Freckleton, R. P., Harvey, P. H. and M. Pagel, M. (2002) Phylogenetic analysis and comparative data: a test and review of evidence. American Naturalist, 160, 712--726.
Pagel, M. (1999) Inferring the historical patterns of biological evolution. Nature, 401,877--884.