cdata offers several different synataxes
for item selection and slicing.
These fall into two main categories:</p>
<ul class="simple">
<li><p><em>numbered</em> indexing and slicing. These will be familiar to most users of python, but require the addition of the dimension name.</p></li>
</ul>
<p>and</p>
<ul class="simple">
<li><p><em>axis-coordinate-based</em>.  These use the natural axis coordinates.  For example, you can specify a range of frequencies, <em>etc.</em>, directly, and with a <em>very compact</e