alue. For CTD data, the
<code>"boxcar"</code> method may be the preferred choice, because the task is normally
to sub-sample, and some degree of smoothing is usually desired.  (The
<code>"lm"</code> method can be quite slow, and its results may be quite similar to those of the
boxcar method.)</p>
<p>For widely-spaced data, a sort of numerical cabbeling effect can result when
density is computed based on interpolated salinity and temperature.
See reference 2 for a discussion of this issue and possible soluti