% \VignetteIndexEntry{AIDS - Semiparametric Mixed Model}
% \VignetteDepends{mgcv}
%\VignetteEngine{knitr::knitr}
%\VignetteEncoding{UTF-8}
\documentclass[a4paper]{article}

\title{AIDS - Semiparametric Mixed Model}

\begin{document}

\maketitle


<<echo=FALSE,eval=FALSE>>=
options(width=80)
@

The "AIDS"--data from "catdata" are loaded.

<<eval=FALSE>>=
library(catdata)
data(aids)
@

As for normal GAMs for GAMMs the package "mgcv" is used.

<<eval=FALSE>>=
library(mgcv)
@

The Semiparametric Mixed Model (or Generalized Additive Mixed Model) for "AIDS"--Data is fitted by the function "gamm". Here the only random effect is 
the random intercept.

<<eval=FALSE>>=
gammaids<-gamm(cd4 ~ s(time) + drugs + partners + s(cesd) + s(age), 
               random=list(person=~1),  family=poisson(link=log), data=aids)
@

The summary of the fixed effects is printed.

<<eval=FALSE>>=
summary(gammaids$gam)
@

Finally the three smooth effects from the gam are plotted.

<<fig.width=12, fig.height=9,eval=FALSE>>=
plot(gammaids$gam,ylab=" ",cex.lab=1.8,cex.axis=1.5,select=1)
@

<<fig.width=12, fig.height=9,eval=FALSE>>=
plot(gammaids$gam,ylab=" ",cex.lab=1.8,cex.axis=1.5,select=2)
@


<<fig.width=12, fig.height=9,eval=FALSE>>=
plot(gammaids$gam,ylab=" ",cex.lab=1.8,cex.axis=1.5,select=3)
@
<<echo=FALSE,results='hide',eval=FALSE>>=
detach(package:mgcv)
@

\end{document}
