Problem 645. Getting the indices from a vector

Created by Doug Hull

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>This is a basic MATLAB operation. It is for instructional purposes.</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:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>You may already know how to</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"http://www.mathworks.com/matlabcentral/cody/problems/640-do-a-binary-comparison-on-a-vector\"><w:r><w:t>find the logical indices</w:t></w:r></w:hyperlink><w:r><w:t> of the elements of a vector that meet your criteria.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>This exercise is for finding the index of indices that meet your criteria. The difference is this:</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[     vec = [11 22 33 44];\n  thresh = 25;\n      vi = (vec > thresh)\n\nvi =\n\n     0     0     1     1]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>What we are looking for now is how to get the values</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"code\"/></w:pPr><w:r><w:t><![CDATA[   x =\n\n     3     4]]></w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Because those are the indices where the binary comparison is true.</w:t></w:r></w:p><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Check out</w:t></w:r><w:r><w:t> </w:t></w:r><w:hyperlink w:docLocation=\"http://www.mathworks.com/help/techdoc/ref/find.html\"><w:r><w:t>find</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>Given a vector, vec, return the indices where vec is greater than scalar, thresh.</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

5744 Solutions
3222 Solvers

Last Solution submitted on Jan 24, 2021

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

goc3 on 18 Nov 2016

I added six more test cases.

Nguyen Huu Hung on 14 Sep 2019

hay

Kerem Kutan on 12 Jun 2020

kinda easy

Miriam Sánchez Fernández on 7 Nov 2020

It's easy with function "find"

Benjamin Hoehne on 1 Dec 2020

use "find"

Solution Comments

Solution 3899893

1 Comment

1 Comment

Qingyin Zhang on 29 Nov 2020

out=find(vec>thresh);

Solution 3579645

Solution 3012838

1 Comment

1 Comment

Darren Nixon on 1 Oct 2020

out=find(double(vec>thresh)>0);

Solution 1936830

1 Comment

1 Comment

Umur Ulas Harman on 25 Jun 2020

function out = findIndices(vec, thresh)
[row,col]=find(vec>thresh);
out = col
end

Solution 1623474

2 Comments

2 Comments

Ahsan Naseer on 15 Sep 2018

my solution is incorrect.how would i get the exact solution?

Tavish Pattanayak on 8 May 2020

You can ask in the matlab center

Solution 382087

1 Comment

1 Comment

SJ Won on 2 Jul 2019

Can someone explain this solution to me?

Problem Recent Solvers3222

Problem Tags

Community Treasure Hunt

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

Start Hunting!

Problem 645. Getting the indices from a vector

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers3222

Suggested Problems

More from this Author52

Problem Tags

Community Treasure Hunt

Problem 645. Getting the indices from a vector

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers3222

Suggested Problems

More from this Author52

Problem Tags

Community Treasure Hunt

Players