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&#160;<span id="projectnumber">3.9.1dev</span>
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<li class="navelem"><a class="el" href="namespacegeos.html">geos</a></li><li class="navelem"><a class="el" href="namespacegeos_1_1index.html">index</a></li><li class="navelem"><a class="el" href="namespacegeos_1_1index_1_1quadtree.html">quadtree</a></li><li class="navelem"><a class="el" href="classgeos_1_1index_1_1quadtree_1_1IntervalSize.html">IntervalSize</a></li> </ul>
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<p>Provides a test for whether an interval is so small it should be considered as zero for the purposes of inserting it into a binary tree.
<a href="classgeos_1_1index_1_1quadtree_1_1IntervalSize.html#details">More...</a></p>
<p><code>#include &lt;<a class="el" href="IntervalSize_8h_source.html">IntervalSize.h</a>&gt;</code></p>
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<tr class="memitem:a46b260e9813d9e9164e7a120393ae3c0"><td class="memItemLeft" align="right" valign="top">static bool&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1index_1_1quadtree_1_1IntervalSize.html#a46b260e9813d9e9164e7a120393ae3c0">isZeroWidth</a> (double min, double max)</td></tr>
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<tr class="memitem:ac2ba899e2a7dee33869bb5d564b5312d"><td class="memItemLeft" align="right" valign="top">static const int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1index_1_1quadtree_1_1IntervalSize.html#ac2ba899e2a7dee33869bb5d564b5312d">MIN_BINARY_EXPONENT</a> = -50</td></tr>
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<div class="textblock"><p>Provides a test for whether an interval is so small it should be considered as zero for the purposes of inserting it into a binary tree. </p>
<p>The reason this check is necessary is that round-off error can cause the algorithm used to subdivide an interval to fail, by computing a midpoint value which does not lie strictly between the endpoints. </p>
<p>Definition at line <a class="el" href="IntervalSize_8h_source.html#l00041">41</a> of file <a class="el" href="IntervalSize_8h_source.html">IntervalSize.h</a>.</p>
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<td class="memname">static bool geos::index::quadtree::IntervalSize::isZeroWidth </td>
<td>(</td>
<td class="paramtype">double&#160;</td>
<td class="paramname"><em>min</em>, </td>
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<td class="paramtype">double&#160;</td>
<td class="paramname"><em>max</em>&#160;</td>
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<p>Computes whether the interval [min, max] is effectively zero width. I.e. the width of the interval is so much less than the location of the interval that the midpoint of the interval cannot be represented precisely. </p>
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<td class="memname">const int geos::index::quadtree::IntervalSize::MIN_BINARY_EXPONENT = -50</td>
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<p>This value is chosen to be a few powers of 2 less than the number of bits available in the double representation (i.e. 53). This should allow enough extra precision for simple computations to be correct, at least for comparison purposes. </p>
<p>Definition at line <a class="el" href="IntervalSize_8h_source.html#l00049">49</a> of file <a class="el" href="IntervalSize_8h_source.html">IntervalSize.h</a>.</p>
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<hr/>The documentation for this class was generated from the following file:<ul>
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