lmeBM {covBM} R Documentation

## lmeBM

### Description

This function is a wrapper for lme.formula that allows Brownian motion, fractional Brownian motion or integrated Ornstein-Uhlenbeck components to be included in linear mixed models, with related parameter estimates and confidence intervals returned in their natural parameterisation.

### Usage

lmeBM(fixed, data, random, covariance = NULL, method = c("REML", "ML"),
control = list(), keep.data = TRUE)


### Arguments

 fixed This is as specified for lme.formula. data This is as specified for lme.formula. random This is as specified for lme.formula. covariance An optional corStruct object describing the within-group covariance structure. In addition to those available in nlme, covBM can be used to incorporate a Brownian motion component, covFracBM can be used to incorporate a fractional Brownian motion component and covIOU can be used to incorporate an integrated Ornstein-Uhlenbeck process in relation to a continuous variable. method This is as specified for lme.formula. control This is as specified for lme.formula. keep.data This is as specified for lme.formula.

### Value

An object of class "lme" representing the linear mixed effects model fit.

### Examples

BMmodel<-lmeBM(sqrtcd4~t, data=cd4, random=~t|newpid, covariance=covBM(form=~t|newpid),