inst/doc/varTestnlme.R

In varTestnlme: Variance Components Testing for Linear and Nonlinear Mixed Effects Models

## ---- include = FALSE---------------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

## ----setup--------------------------------------------------------------------
library(varTestnlme)

## ---- message=FALSE-----------------------------------------------------------
# Load the packages
library(nlme)
library(lme4)
library(saemix)
library(EnvStats)

## ----results='hide', message=FALSE--------------------------------------------
data("Orthodont")

# using nlme, with correlated slope and intercept
m1.nlme <- lme(distance ~ 1 + Sex + age + age*Sex, random = pdSymm(Subject ~ 1 + age), data = Orthodont, method = "ML")
m0.nlme <- lme(distance ~ 1 + Sex + age + age*Sex, random = ~ 1 | Subject, data = Orthodont, method = "ML")

# using lme4, with correlated slope and intercept
m1.lme4 <- lmer(distance ~ 1 + Sex + age + age*Sex + (1 + age | Subject), data = Orthodont, REML = FALSE)
m0.lme4 <- lmer(distance ~ 1 + Sex + age + age*Sex + (1 | Subject), data = Orthodont, REML = FALSE)


## -----------------------------------------------------------------------------
vt1.nlme <- varCompTest(m1.nlme,m0.nlme)
vt1.lme4 <- varCompTest(m1.lme4,m0.lme4)

## -----------------------------------------------------------------------------
print(vt1.nlme)

## -----------------------------------------------------------------------------
vt1.nlme$statistic
vt1.nlme$p.value

## -----------------------------------------------------------------------------
# using nlme, with uncorrelated slope and intercept
m1diag.nlme <- lme(distance ~ 1 + Sex + age + age*Sex, random = pdDiag(Subject ~ 1 + age), data = Orthodont, method = "ML")

# using lme4, with uncorrelated slope and intercept
m1diag.lme4 <- lmer(distance ~ 1 + Sex + age + age*Sex + (1 + age || Subject), data = Orthodont, REML = FALSE)

vt1diag.nlme <- varCompTest(m1diag.nlme,m0.nlme)
vt1diag.lme4 <- varCompTest(m1diag.lme4,m0.lme4)

## -----------------------------------------------------------------------------
m0noRE <- lm(distance ~ 1 + Sex + age + age*Sex, data = Orthodont)

vt <- varCompTest(m1diag.nlme,m0noRE,pval.comp = "both")
vt2 <- varCompTest(m1diag.lme4,m0noRE)

## ---- eval=FALSE--------------------------------------------------------------
#  varCompTest(m1diag.nlme, m0noRE, fim = "compute", pval.comp = "both", control = list(B=100))
#  varCompTest(m1diag.lme4, m0noRE, fim = "compute", pval.comp = "both", control = list(B=100))

## -----------------------------------------------------------------------------
m1 <- glmer(cbind(incidence, size - incidence) ~ period + (1 | herd),
             family = binomial, data = cbpp)
m0 <- glm(cbind(incidence, size - incidence) ~ period,
             family = binomial, data = cbpp)
varCompTest(m1,m0)

## -----------------------------------------------------------------------------
# with nlme
fm1Theo.nlme <- nlme(conc ~ SSfol(Dose, Time, lKe, lKa, lCl),
                     Theoph,
                     fixed = lKe + lKa + lCl ~ 1,
                     start=c( -2.4, 0.45, -3.2),
                     random = pdSymm(lKa + lCl ~ 1))
fm2Theo.nlme <- nlme(conc ~ SSfol(Dose, Time, lKe, lKa, lCl),
                     Theoph,
                     fixed = lKe + lKa + lCl ~ 1,
                     start=c( -2.4, 0.45, -3.2),
                     random = pdDiag(lCl ~ 1))
varCompTest(fm1Theo.nlme,fm2Theo.nlme)

## -----------------------------------------------------------------------------
# with lme4
Th.start  <- c(lKe = -2.4, lKa = 0.45, lCl = -3.2)
nm1  <- nlmer(conc ~ SSfol(Dose , Time ,lKe , lKa , lCl) ~
                0+lKe+lKa+lCl +(lKe+lKa+lCl|Subject),
              nAGQ=0,
              Theoph,
              start = Th.start)
nm0  <- nlmer(conc ~ SSfol(Dose , Time ,lKe , lKa , lCl) ~
                0+lKe+lKa+lCl +(lKa+lCl|Subject),
              nAGQ=0,
              Theoph,
              start = Th.start)
varCompTest(nm1,nm0)

## -----------------------------------------------------------------------------
fm1 <- nlme(conc ~ SSfol(Dose, Time, lKe, lKa, lCl),
                     Theoph,
                     fixed = lKe + lKa + lCl ~ 1,
                     start=c( -2.4, 0.45, -3.2),
                     random = pdDiag(lKe + lKa + lCl ~ 1))
fm0 <- nls(conc ~ SSfol(Dose, Time, lKe, lKa, lCl),
                     Theoph,
                     start=list(lKe=-2.4,lKa=0.45,lCl=-3.2))
varCompTest(fm1,fm0)