phyl.RMA: Phylogenetic reduced major axis (RMA) regression
Description
This function performs phylogenetic RMA regression.
Usage
phyl.RMA(x, y, tree, method="BM", lambda=NULL, fixed=FALSE, h0=1.0)
Arguments
tree
a phylogenetic tree in "phylo"
format.
method
method to obtain the correlation structure: can be "BM"
or "lambda"
.
lambda
value of lambda
for fixed $\lambda$.
fixed
logical value indicating whether or not $\lambda$ should be optimized using likelihood.
h0
null hypothesis for beta
. Defaults to 1.0. Note that a null hypothesis of 0.0 is not allowed.
Value
A list with the following components:
Details
Optionally jointly estimates lambda if method="lambda"
. Likelihood optimization of lambda is performed using optimize
on the interval (0,1). Note that some statistician think there is never a condition in which a reduced-major-axis regression should be used.
References
Revell, L. J. (2012) phytools: An R package for phylogenetic comparative biology (and other things). Methods Ecol. Evol., 3, 217-223.