nlmeBM {covBM} R Documentation

## nlmeBM

### Description

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

### Usage

nlmeBM(model, data, fixed, random, start, covariance = NULL,
method = c("ML", "REML"), control = list(), verbose = FALSE)


### Arguments

 model This is as specified for nlme.formula. data This is as specified for lme.formula. fixed This is as specified for lme.formula. random This is as specified for nlme.formula. start This is as specified for nlme.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 nlme.formula. verbose This is as specified for nlme.formula.

### Value

An object of class "nlme" and inheriting from class "lme" representing the non-linear mixed effects model fit.

### Examples

data(Milk, package="nlme")
Model_fit<- nlmeBM(protein ~ SSasymp(Time, Asym, R0, lrc), data=Milk,
fixed = Asym + R0 + lrc ~ 1, random = Asym ~ 1|Cow,
covariance=covFracBM(form=~Time|Cow),
start = c(Asym = 3.5, R0 = 4, lrc = -1))


[Package covBM version 0.1.0 Index]