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<p>My understanding is that it isn't griding or making up new points
or aggregating points or anything like that. It returns a subset
of the original points. Which points it returns depends on what
level of the ept tree that each of the original points was placed
into when the tree was created. The resolution parameter
determines how many levels of the tree PDAL pulls points from.<br>
</p>
<p>As far as I can tell it takes no regard for non-spatial
dimensions such as classification. So, there isn't a direct way
to for example query for only ground points at a certain
resolution. You have to query for all points and then filter out
the ones that aren't ground (which will likely leave you with a
lower resolution than you initially queried for in your final
result).<br>
</p>
<div class="moz-cite-prefix">On 3/25/19 1:48 PM, Matt Beckley wrote:<br>
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<blockquote type="cite"
cite="mid:CACrek76RUUEM+FgvNatDMCSkGcPkCw2NuwoZzu_MXakX+ftbCg@mail.gmail.com">
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<div>Is there more information available regarding how the
'resolution' keyword works for the latest version of
readers.ept? Is it "gridding" the data at a specified cell
size? If so, how does it handle nominal class data such as
lidar classifications? Is it taking the first, last, or a
random sample to assign as the classification for each
cell(assuming a scenario where there are multiple
classifications that fall within a given cell). In other
words, how is the defining classification assigned for each
cell given a sample of points with varied classification
values?</div>
<div><br>
</div>
<div><a
href="https://github.com/PDAL/PDAL/blob/master/doc/stages/readers.ept.rst"
target="_blank" moz-do-not-send="true">https://github.com/PDAL/PDAL/blob/master/doc/stages/readers.ept.rst</a><br>
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<div><br>
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<div>Thanks!</div>
<div><br>
</div>
<div>matt.</div>
<div><br>
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<div dir="ltr">---------------------------
<div>Matthew Beckley</div>
<div>Data Engineer</div>
<div>UNAVCO/OpenTopography</div>
<div><a href="mailto:beckley@unavco.org"
target="_blank" moz-do-not-send="true">beckley@unavco.org</a></div>
303-381-7487</div>
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