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phytools (version 0.5-64)

brownie.lite: Likelihood test for rate variation in a continuous trait

Description

This function takes a modified "phylo" object with a mapped binary or multistate trait (see read.simmap) and data for a single continuously valued character. It then fits the Brownian rate variation ("noncensored") model of O'Meara et al. (2006; Evolution). This is also the basic model implemented in Brian O'Meara's "Brownie" program.

Usage

brownie.lite(tree, x, maxit=2000, test="chisq", nsim=100, se=NULL, ...)

Arguments

tree
a phylogenetic tree in modified "phylo" format (see read.simmap, make.simmap, or paintSubTree).
x
a vector of tip values for species; names(x) should be the species names.
maxit
an optional integer value indicating the maximum number of iterations for optimization - may need to be increased for large trees.
test
an optional string indicating the method for hypothesis testing - options are "chisq" or "simulation".
nsim
number of simulations (only used if test="simulation").
se
a vector containing the standard errors for each estimated mean in x.
...
optional arguments.

Value

A list with the following components:

Details

Sampling error in the estimation of species means can also be accounted for by assigning the vector se with the species specific sampling errors for x.

References

O'Meara, B. C., C. Ane, M. J. Sanderson, and P. C. Wainwright. (2006) Testing for different rates of continuous trait evolution using likelihood. Evolution, 60, 922--933.

Revell, L. J. (2012) phytools: An R package for phylogenetic comparative biology (and other things). Methods Ecol. Evol., 3, 217-223.

See Also

brownieREML, evol.vcv