nlmeBM: nlmeBM

In covBM: Brownian Motion Processes for 'nlme'-Models

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))

covBM documentation built on May 1, 2019, 7:53 p.m.