<!-- We will use xml comments. There must be only ONE document root. -->
<talk name="Swiss">

<!-- SECTION 1. summary method -->
<section name="Methods" button="TRUE">

<text break="T">
This short talk examines the "summary" method
and applies it to the "swiss" dataset.</text>
<text break="T">
The talk itself comes from a talk description file.
The next step should open that file (swisstalk.xml),
provided that a program is associated with xml files. </text>

<file name="swisstalk" button="TRUE">swisstalk.xml</file>

<text break="F">
"summary" is a function (class function). </text>

<code break="print">
isWhat(summary) # isWhat() from PBSmodelling</code>
<text break="F">"summary" is generic:</text>
<code break="print">summary</code>
<text break="F">"summary" has many methods:</text>
<code break="print"> methods(summary)</code>

</section>

<!-- SECTION 2. The "swiss" data -->
<section name="Data" button="TRUE">

<text break="F"> "swiss" is a data frame (class data.frame):</text>
<code> isWhat(swiss)</code>
<text break="F"> You can read about the data here:</text>
<code> help(swiss) # open the help file</code>
<text break="F"> Apply "summary" to Swiss:</text>
<code break="print"> summary(swiss)</code>
<text break="F"> Print the first 3 records:</text>
<code break="print"> head(swiss,3)</code>
<text break="F"> Display the data with the "plot" method . . .</text>
<code print="F"> plot(swiss,gap=0)</code>
<text> THE END .. THANKS FOR WATCHING!</text>

</section>
</talk>
