Problem 2592. LocateMembership | Membership of Matrix in another matrix

Created by Vishal

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>Let a and b be given by</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[ a = [ 2 1 1 1   \n       1 2 1 1 \n       1 1 2 1 \n       1 1 1 2\n       4 0 0 0 ] \n\n b = [ 2 1 1\n       1 2 1\n       1 1 2 ]]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>then b can be created using a (b is wholly present in a). So output should be location of central element of b in a.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Here output is [3,3] else it should be [0,0].</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

47 Solutions
19 Solvers

Last Solution submitted on Apr 03, 2022

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

rifat on 16 Sep 2014

in test case 3, b is not available in a. I might be wrong.. Please Check

Jean-Marie Sainthillier on 16 Sep 2014

Not logic to ask a scalar (if no location), an array (if 1), and a cell (if 2). And why not add the example (difficult) in the tests ?

Vishal on 17 Sep 2014

@rifat : updated, thanks for info

Jan Orwat on 18 Sep 2014

Nice problem. Some solutions (using conv, filter2 etc.) doesn't check conditions properly. Adding a=2*ones(4); b=3*eye(3)+1; or a=0; b=0; or similar can improve the testsuite;

Jean-Marie Sainthillier on 18 Sep 2014

The solution in the example is [2 2;3 3].

Solution Comments

Solution 502674

3 Comments

3 Comments

rifat on 18 Sep 2014

@Jean-Marie, using ismember(a,b) and comparing it with a 2D window of ones works in this particular case. But, ismember does not consider the order of the elements. You can verify this by calling LocateMembership(a,b') for the second test case. You would see that it results [2 4] though it is not correct.

Jean-Marie Sainthillier on 18 Sep 2014

@rifat, you're right. At the beginning, before the first corrections, I thought it was the goal of this problem (b can be created using a in any order) and I kept this approach.By the way @Vishal, it's a very interesting problem !

Vishal on 19 Sep 2014

@Jean - Thanks.

Problem Recent Solvers19

Problem Tags

matrix manipulation

Community Treasure Hunt

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

Start Hunting!

Problem 2592. LocateMembership | Membership of Matrix in another matrix

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers19

Suggested Problems

More from this Author6

Problem Tags

Community Treasure Hunt

Problem 2592. LocateMembership | Membership of Matrix in another matrix

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers19

Suggested Problems

More from this Author6

Problem Tags

Community Treasure Hunt

Players