es of things that can be accessed with <code>[[</code>.
The <code>data</code> and <code>metadata</code> items hold the names of
entries in the object's data and metadata
slots, respectively. The <code>dataDerived</code>
and <code>metadataDerived</code> items are each NULL, because
no derived values are defined for <a href="coastline-class.html">coastline</a> objects.</p></li>
<li><p>In many cases, the focus will be on the coastline trace
in longitude-latitude space, so <code>x[["longitude"]]</code>
and <cod