% \VignetteIndexEntry{Number of Children - Partially Additive Model}
% \VignetteDepends{mgcv}
%\VignetteEngine{knitr::knitr}
%\VignetteEncoding{UTF-8}
\documentclass[a4paper]{article}

\title{Number of Children - Partially Additive Model}

\begin{document}

\maketitle


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

For the following partially additive model  the "children"--data from the package "catdata" are used. 

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

Additive Models are  fitted with the function "gam" from "mgcv".

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

Here the model is fitted and the summary is printed.

<<eval=FALSE>>=
gamchild <- gam(child ~ s(age) + s(dur) + as.factor(nation) + as.factor(god) + 
  as.factor(univ), data=children, family=poisson(link=log))

summary(gamchild)
@

Now the smooth effects can be plotted, the option "select" determines which effect is plotted.

<<fig.width=9,eval=FALSE>>=
par(cex=1.5)
plot(gamchild, select=1, ylab="", xlab="Age")
@

<<fig.width=9,eval=FALSE>>=
par(cex=1.5)
plot(gamchild, select=2, ylab="", xlab="Duration")
@


\end{document}