3 \alias{coef.corBlomberg}
4 \alias{corMatrix.corBlomberg}
5 \title{Blomberg et al.'s Correlation Structure}
7 corBlomberg(value, phy, form = ~1, fixed = FALSE)
8 \method{corMatrix}{corBlomberg}(object, covariate = getCovariate(object),
10 \method{coef}{corBlomberg}(object, unconstrained = TRUE, \dots)
13 \item{value}{the (initial) value of the parameter \eqn{g}{g}.}
14 \item{phy}{an object of class \code{"phylo"}.}
15 \item{form}{(ignored).}
16 \item{fixed}{a logical specifying whether \code{gls} should
17 estimate \eqn{\gamma}{gamma} (the default) or keep it fixed.}
18 \item{object}{an (initialized) object of class \code{"corBlomberg"}.}
19 \item{covariate}{(ignored).}
20 \item{corr}{a logical value specifying whether to return the
21 correlation matrix (the default) or the variance-covariance matrix.}
22 \item{unconstrained}{a logical value. If \code{TRUE} (the default),
23 the coefficients are returned in unconstrained form (the same used
24 in the optimization algorithm). If \code{FALSE} the coefficients are
25 returned in ``natural'', possibly constrained, form.}
26 \item{\dots}{further arguments passed to or from other methods.}
29 The ``ACDC'' (accelerated/decelerated) model assumes that continuous
30 traits evolve under a Brownian motion model which rates accelerates
31 (if \eqn{g}{g} < 1) or decelerates (if \eqn{g}{g} > 1) through
32 time. If \eqn{g}{g} = 1, then the model reduces to a Brownian motion
36 an object of class \code{"corBlomberg"}, the coefficients from an
37 object of this class, or the correlation matrix of an initialized
38 object of this class. In most situations, only \code{corBlomberg} will
39 be called by the user.
41 \author{Emmanuel Paradis}
43 Blomberg, S. P., Garland, Jr, T., and Ives, A. R. (2003) Testing for
44 phylogenetic signal in comparative data: behavioral traits are more
45 labile. \emph{Evolution}, \bold{57}, 717--745.