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

8897 Solutions
5065 Solvers

Last Solution submitted on Jan 22, 2022

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 6810970

1 Comment

1 Comment

Josh Klueber on 2 Nov 2021

good problem

Solution 6704236

Solution 6012825

1 Comment

1 Comment

Kossel E. LEGUEZIM on 25 Jun 2021

Nice problem!

Solution 5670635

1 Comment

1 Comment

john perkins on 4 May 2021

very cool problem

Solution 5420785

1 Comment

1 Comment

TIMOTHY PIERGIOVANNI on 21 Apr 2021

find() function

Solution 3899893

1 Comment

1 Comment

Qingyin Zhang on 29 Nov 2020

out=find(vec>thresh);

Solution 3579645

Solution 3012838

1 Comment

1 Comment

Isabella Stellitano on 4 Nov 2021

good problem

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

Problem Recent Solvers5065

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 Solvers5065

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 Solvers5065

Suggested Problems

More from this Author52

Problem Tags

Community Treasure Hunt

Players