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<title>GEOS: geos::index::quadtree::IntervalSize Class Reference</title>
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<li><a class="el" href="classgeos_1_1index_1_1quadtree_1_1IntervalSize.html">geos::index::quadtree::IntervalSize</a> </li>
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<a href="#pub-static-methods">Static Public Member Functions</a> |
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<h1>geos::index::quadtree::IntervalSize Class Reference</h1> </div>
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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="#_details">More...</a></p>
<p><code>#include <<a class="el" href="indexQuadtree_8h_source.html">geos/indexQuadtree.h</a>></code></p>
<p><a href="classgeos_1_1index_1_1quadtree_1_1IntervalSize-members.html">List of all members.</a></p>
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<tr><td colspan="2"><h2><a name="pub-static-methods"></a>
Static Public Member Functions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">static bool </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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Static Public Attributes</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">static const int </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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<hr/><a name="_details"></a><h2>Detailed Description</h2>
<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>
<hr/><h2>Member Function Documentation</h2>
<a class="anchor" id="a46b260e9813d9e9164e7a120393ae3c0"></a><!-- doxytag: member="geos::index::quadtree::IntervalSize::isZeroWidth" ref="a46b260e9813d9e9164e7a120393ae3c0" args="(double min, double max)" -->
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<td class="memname">static bool geos::index::quadtree::IntervalSize::isZeroWidth </td>
<td>(</td>
<td class="paramtype">double </td>
<td class="paramname"> <em>min</em>, </td>
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<td class="paramtype">double </td>
<td class="paramname"> <em>max</em></td><td> </td>
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<td>)</td>
<td></td><td></td><td><code> [static]</code></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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<hr/><h2>Member Data Documentation</h2>
<a class="anchor" id="ac2ba899e2a7dee33869bb5d564b5312d"></a><!-- doxytag: member="geos::index::quadtree::IntervalSize::MIN_BINARY_EXPONENT" ref="ac2ba899e2a7dee33869bb5d564b5312d" args="" -->
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<td class="memname">const int <a class="el" href="classgeos_1_1index_1_1quadtree_1_1IntervalSize.html#ac2ba899e2a7dee33869bb5d564b5312d">geos::index::quadtree::IntervalSize::MIN_BINARY_EXPONENT</a> = -50<code> [static]</code></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>
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<hr/>The documentation for this class was generated from the following file:<ul>
<li><a class="el" href="IntervalSize_8h_source.html">IntervalSize.h</a></li>
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