Problem 44352. The Top 5 Primes

Created by Peng Liu

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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>This problem series invites you to solve two simple problems related to the integer NUMBER FIVE, in order to celebrate</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"https://www.mathworks.com/matlabcentral/cody/contests/1?s_tid=Cody5YA_cody_home\"><w:r><w:t>Cody's 5th birthday</w:t></w:r></w:hyperlink><w:r><w:t>.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>In this problem, let's find the top 5 greatest prime numbers along the first non-singleton dimension of an input array.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Example</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>If the input is a vector, the output is a length-5 vector containing the top 5 prime numbers of the input sorted in descending order. Append NaNs as needed in the output if the number of primes is less than 5.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[x = 1:10;\ny = [7 5 3 2 NaN];]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"ListParagraph\"/><w:numPr><w:numId w:val=\"1\"/></w:numPr></w:pPr><w:r><w:t>If the input is a m-by-n (m &gt;= 5) matrix, the output is a 5-by-n matrix containing the column-wise top 5 prime numbers of the input matrix sorted in descending order. Whenever there are less than 5 primes found in a specific column of the input, simply append NaNs as needed in the same column of the output.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[% Input x is a matrix\nx = [17 6 3\n 13 8 17\n 1 2 5\n 5 3 7\n 7 11 2\n 31 7 6];\n\n% Output y\ny = [31 11 17\n 17 7 7\n 13 3 5\n 7 2 3\n 5 NaN 2];]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Previous problem in this series:</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"https://www.mathworks.com/matlabcentral/cody/problems/44342-spot-the-first-occurrence-of-5\"><w:r><w:t>Spot the First Occurrence of 5</w:t></w:r></w:hyperlink></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>"}]}

This problem series invites you to solve two simple problems related to the integer NUMBER FIVE, in order to celebrate <a href = "https://www.mathworks.com/matlabcentral/cody/contests/1?s_tid=Cody5YA_cody_home">Cody's 5th birthday</a>.In this problem, let's find the top 5 greatest prime numbers along the first non-singleton dimension of an input array.Example<ul><li>If the input is a vector, the output is a length-5 vector containing the top 5 prime numbers of the input sorted in descending order. Append NaNs as needed in the output if the number of primes is less than 5.</li></ul><pre class="language-matlab">x = 1:10;
y = [7 5 3 2 NaN];
</pre><ul><li>If the input is a m-by-n (m &gt;= 5) matrix, the output is a 5-by-n matrix containing the column-wise top 5 prime numbers of the input matrix sorted in descending order. Whenever there are less than 5 primes found in a specific column of the input, simply append NaNs as needed in the same column of the output.</li></ul><pre class="language-matlab">% Input x is a matrix
x = [17 6 3
 13 8 17
 1 2 5
 5 3 7
 7 11 2
 31 7 6];
</pre><pre class="language-matlab">% Output y
y = [31 11 17
 17 7 7
 13 3 5
 7 2 3
 5 NaN 2];
</pre>Previous problem in this series: <a href = "https://www.mathworks.com/matlabcentral/cody/problems/44342-spot-the-first-occurrence-of-5">Spot the First Occurrence of 5</a>

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Problem 44352. The Top 5 Primes

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