Problem 214. Filter values in a vector

Created by Arthur Goldsipe

Solve Later

{"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>Cody often benefits from a functional style of programming. For example, your score is often better when you compose multiple functions instead of using intermediate variables. This problem involves creating a function to expand the repertoire of \"functional functions.\"</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>For this problem, write a filter function that applies a \"predicate\" function to a numeric, character, or cell vector and returns the elements for which the predicate returns true. Here are few examples:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[filterfun(@isprime, 1:10)                     ==> [2 3 5 7]\nfilterfun(@(c)c~='a', 'kayak radar')          ==> 'kyk rdr'\nfilterfun(@(x)~isempty(x), {[]; 1; 'a'; []; {}}') ==> {1; 'a'}]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Notes: If the vector</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:rFonts w:cs=\"monospace\"/></w:rPr><w:t>v</w:t></w:r><w:r><w:t> is a cell, you should apply the predicate to</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:rFonts w:cs=\"monospace\"/></w:rPr><w:t>v{i}</w:t></w:r><w:r><w:t> not</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:rFonts w:cs=\"monospace\"/></w:rPr><w:t>v(i)</w:t></w:r><w:r><w:t>. Also,</w:t></w:r><w:r><w:t> </w:t></w:r><w:r><w:rPr><w:rFonts w:cs=\"monospace\"/></w:rPr><w:t>filterfun</w:t></w:r><w:r><w:t> should preserve the singleton dimension of the vector, i.e. if the input vector is a column vector the output should be a column vector.</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>"}]}

Solve

Solution Stats

221 Solutions
70 Solvers

Last Solution submitted on Jan 28, 2023

Last 200 Solutions

Problem Comments

1 Comment

1 Comment

David Young on 29 Feb 2012

I think the third example in the problem statement is incorrect. The input is a row (it's set up as a column, but then is transposed), but the output is a column.

Solution Comments

Solution 52357

1 Comment

1 Comment

Raphael Cautain on 27 Feb 2012

There may have some limitations when resulting rows are with different lengthes.

Problem Recent Solvers70

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 214. Filter values in a vector

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers70

Suggested Problems

More from this Author1

Problem Tags

Community Treasure Hunt

Problem 214. Filter values in a vector

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers70

Suggested Problems

More from this Author1

Problem Tags

Community Treasure Hunt

Players