Problem 45256. Query a vertex neighbors

Created by Nicolas Douillet

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{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","targetMode":"","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","targetMode":"","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>First input T is a triangulation connectivity indices list (triplet list of indices -positive integers-, each index refering to a vertex number in a corresponding vertices list).</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Second input i is a vertex index (positive integer).</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>The purpose of this function is to query the list L of all i neighbor indices.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>For instance if</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[T = [1 2 4;...\n 2 3 4;...\n 5 6 8;...\n 6 7 8;...\n 1 2 5;...\n 2 5 6;...\n 2 3 6;...\n 3 6 7;...\n 3 4 7;...\n 4 7 8;...\n 4 1 8;...\n 1 8 5]]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>and i = 3, then the function should return</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[L = [2, 4, 6, 7]]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>since 2, 4, 6, and 7 are all part of triangles / rows in which 3 is also a vertex member.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Hypothesis :</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>-</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>Output L</w:t></w:r><w:r><w:t> doesn't need to be ordered, but must</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>not contain duplicated index.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>-</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>Output L is a row vector</w:t></w:r><w:r><w:t> , and</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>if the vertex index is not in the list</w:t></w:r><w:r><w:t> , the function</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:b/></w:rPr><w:t>must of course return the empty set</w:t></w:r><w:r><w:t>, [].</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

First input T is a triangulation connectivity indices list (triplet list of indices -positive integers-, each index refering to a vertex number in a corresponding vertices list).Second input i is a vertex index (positive integer).The purpose of this function is to query the list L of all i neighbor indices.For instance if<pre class="language-matlab">T = [1 2 4;...
 2 3 4;...
 5 6 8;...
 6 7 8;...
 1 2 5;...
 2 5 6;...
 2 3 6;...
 3 6 7;...
 3 4 7;...
 4 7 8;...
 4 1 8;...
 1 8 5]
</pre>and i = 3, then the function should return<pre class="language-matlab">L = [2, 4, 6, 7]
</pre>since 2, 4, 6, and 7 are all part of triangles / rows in which 3 is also a vertex member.Hypothesis :- Output L doesn't need to be ordered, but must not contain duplicated index.- Output L is a row vector , and if the vertex index is not in the list , the function must of course return the empty set, [].

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Last Solution submitted on Sep 18, 2020

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3d edge face facet find geometry index indices mathematics mesh mesh processing neighbor surface triangle triangulation trimesh vertex vertices

Problem 45256. Query a vertex neighbors

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Problem 45256. Query a vertex neighbors

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