X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=man%2Face.Rd;h=96860220b2cef50008075f1abe6f72afff7ffac7;hb=1df144a18356d9b329324324bc2f78cfdf1cea3d;hp=85cfb210bbbea57af3f7f0786d6b4f4028ea8e89;hpb=fe18d99e0a288498b3c52391045c1f154887d085;p=ape.git diff --git a/man/ace.Rd b/man/ace.Rd index 85cfb21..9686022 100644 --- a/man/ace.Rd +++ b/man/ace.Rd @@ -1,5 +1,6 @@ \name{ace} \alias{ace} +\alias{print.ace} \alias{logLik.ace} \alias{deviance.ace} \alias{AIC.ace} @@ -9,19 +10,21 @@ ace(x, phy, type = "continuous", method = "ML", CI = TRUE, model = if (type == "continuous") "BM" else "ER", scaled = TRUE, kappa = 1, corStruct = NULL, ip = 0.1) +\method{print}{ace}(x, digits = 4, ...) \method{logLik}{ace}(object, ...) \method{deviance}{ace}(object, ...) \method{AIC}{ace}(object, ..., k = 2) \method{anova}{ace}(object, ...) } \arguments{ - \item{x}{a vector or a factor.} + \item{x}{a vector or a factor; an object of class \code{"ace"} in the + case of \code{print}.} \item{phy}{an object of class \code{"phylo"}.} \item{type}{the variable type; either \code{"continuous"} or \code{"discrete"} (or an abbreviation of these).} \item{method}{a character specifying the method used for - estimation. Three choices are possible: \code{"ML"}, \code{"pic"}, - or \code{"GLS"}.} + estimation. Four choices are possible: \code{"ML"}, \code{"REML"}, + \code{"pic"}, or \code{"GLS"}.} \item{CI}{a logical specifying whether to return the 95\% confidence intervals of the ancestral state estimates (for continuous characters) or the likelihood of the different states (for discrete @@ -37,11 +40,12 @@ ace(x, phy, type = "continuous", method = "ML", CI = TRUE, structure to be used (this also gives the assumed model).} \item{ip}{the initial value(s) used for the ML estimation procedure when \code{type == "discrete"} (possibly recycled).} + \item{digits}{the number of digits to be printed.} \item{object}{an object of class \code{"ace"}.} \item{k}{a numeric value giving the penalty per estimated parameter; the default is \code{k = 2} which is the classical Akaike information criterion.} - \item{...}{further arguments passed to or from other methods.} + \item{\dots}{further arguments passed to or from other methods.} } \description{ This function estimates ancestral character states, and the associated @@ -52,7 +56,7 @@ ace(x, phy, type = "continuous", method = "ML", CI = TRUE, Akaike information criterion of a tree. If no such values are available, \code{NULL} is returned. - \code{anova} is another generic function that is used to compare + \code{anova} is another generic function which is used to compare nested models: the significance of the additional parameter(s) is tested with likelihood ratio tests. You must ensure that the models are effectively nested (if they are not, the results will be @@ -67,7 +71,26 @@ ace(x, phy, type = "continuous", method = "ML", CI = TRUE, generalized least squares (\code{method = "GLS"}, Martins and Hansen 1997, Cunningham et al. 1998). In the latter case, the specification of \code{phy} and \code{model} are actually ignored: it is instead - given through a correlation structure with the option \code{corStruct}. + given through a correlation structure with the option + \code{corStruct}. + + In the default setting (i.e., \code{method = "ML"} and \code{model = + "BM"}) the maximum likelihood estimation is done simultaneously on the + ancestral values and the variance of the Brownian motion process; + these estimates are then used to compute the confidence intervals in + the standard way. The REML method first estimates the ancestral value + at the root (aka, the phylogenetic mean), then the variance of the + Brownian motion process is estimated by optimizing the residual + log-likelihood. The ancestral values are finally inferred from the + likelihood function giving these two parameters. If \code{method = + "pic"} or \code{"GLS"}, the confidence intervals are computed using + the expected variances under the model, so they depend only on the + tree. + + It could be shown that, with a continous character, REML results in + unbiased estimates of the variance of the Brownian motion process + while ML gives a downward bias. Therefore, the former is recommanded + over the latter, even though it is not the default. For discrete characters (\code{type = "discrete"}), only maximum likelihood estimation is available (Pagel 1994). The model is @@ -130,8 +153,7 @@ ace(x, phy, type = "continuous", method = "ML", CI = TRUE, Likelihood of ancestor states in adaptive radiation. \emph{Evolution}, \bold{51}, 1699--1711. } -\author{Emmanuel Paradis \email{Emmanuel.Paradis@mpl.ird.fr}, Ben Bolker -\email{bolker@zoo.ufl.edu}} +\author{Emmanuel Paradis, Ben Bolker \email{bolker@zoo.ufl.edu}} \seealso{ \code{\link{corBrownian}}, \code{\link{corGrafen}}, \code{\link{corMartins}}, \code{\link{compar.ou}},