Problem 958. ismember: Enhanced Performance for 'rows' and width - Speed Scoring (66% savings)

Created by Richard Zapor

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>The Challenge is to perform very fast the 'ismember' function for a long and wide array. The width of the array is expanded from 16 to 48.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Fast methods can reduce time by 66%.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>The data is small integer representing data permutations of items like DNA and Rubik's cube faces and orientations.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:rPr><w:b/></w:rPr><w:t>Input:</w:t></w:r><w:r><w:t> Array of uint8 of dimensions (m, 48) with values 0:3</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:rPr><w:b/></w:rPr><w:t>Output:</w:t></w:r><w:r><w:t> Array Equivalent to ismember(A,B,'rows')</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:rPr><w:b/></w:rPr><w:t>Hints:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>1) Columns can be merged to form a reduced number of columns 2) Unique has the option to provide an Array and a sorting Index</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Note: Enhancements to speed usually improve memory allocation issues.</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

19 Solutions
16 Solvers

Last Solution submitted on Apr 08, 2021

Last 200 Solutions

Problem Recent Solvers16

Problem Tags

Community Treasure Hunt

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

Start Hunting!

Problem 958. ismember: Enhanced Performance for 'rows' and width - Speed Scoring (66% savings)

Solution Stats

Last 200 Solutions

Problem Recent Solvers16

Suggested Problems

More from this Author260

Problem Tags

Community Treasure Hunt

Problem 958. ismember: Enhanced Performance for 'rows' and width - Speed Scoring (66% savings)

Solution Stats

Last 200 Solutions

Problem Recent Solvers16

Suggested Problems

More from this Author260

Problem Tags

Community Treasure Hunt

Players