little_helpers/tikz/sketch-0.2.161/Doc/sketch/Statistics.html

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  49 <a name="Statistics"></a>Next:&nbsp;<a rel="next" accesskey="n" href="Bugs-and-anomalies.html#Bugs-and-anomalies">Bugs and anomalies</a>,
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  56 <h5 class="subsubsection">4.4.3.1 Statistics</h5>
  57
  58 <p>For the curious, <code>sketch</code> writes one line of depth sort
  59 statistics.  Here is an example for a large collection of triangles.
  60 <pre class="verbatim">
  61   remark, node=34824 probe=581.9 swap=5 split=2 (in=4 out=6) ols=24851/0
  62 </pre>
  63 It means that 34,824 objects were depth sorted after culling.
  64 For each, an average of 581.9 others had to be checked to
  65 ensure that the initial, approximate ordering was correct.  Among all
  66 these checks, only 5 resulted in swaps to reorder the initial
  67 sort.  In two cases, a correct ordering could not be determined, so
  68 binary space partitions
  69 <a name="index-binary-space-partition-503"></a>were constructed for splitting.  A total of 4
  70 objects (triangles in this case) were inserted in the partitions, and
  71 6 polygons were produced.  Finally, 24,851 &ldquo;last
  72 resort&rdquo; polygon overlap checks were performed after simpler, faster
  73 checks failed to yield conclusive results.  The final /0 is for
  74 line-polygon overlap checks.  For comparison, the statistics for the
  75 last figure in <a href="Overview.html#Overview">Overview</a> follow.
  76 <pre class="verbatim">
  77   remark, node=27 probe=14.6 swap=36 split=15 (in=30 out=45) ols=0/69
  78 </pre>
  79 Note that there was proportionally much more swapping and splitting
  80 activity in this highly connected scene.
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