removing rows containing certain values

281 views (last 30 days)
Seth
Seth on 28 Mar 2016
Edited: Kirby Fears on 28 Mar 2016
i have a 3X3 matrix and i want to delete rows containing values greater than a certain value and values less than another certain value, then store the deleted rows separately. These values lie on the second and third column. thank you

Answers (2)

Kirby Fears
Kirby Fears on 28 Mar 2016
Edited: Kirby Fears on 28 Mar 2016
Seth,
You can create logical indexes with conditional statements, and use the & for "and" as well as | for "or" to combine conditions. The resulting logical index can be used for indexing. Here's an example:
m = magic(3);
idx = (m > 8) | (m < 3);
% using "find" to identify rows where logical idx is true
[delRows,~] = find(idx);
% remove duplicates
delRows = unique(delRows);
% store deleted rows
m_toDelete = m(delRows,:);
% delete rows
m(delRows,:) = [];
Hope this helps.
  1 Comment
Kirby Fears
Kirby Fears on 28 Mar 2016
The method from Azzi's answer is more efficient:
m = magic(3);
idx = any((m > 8) | (m < 3),2);
% store deleted rows
m_toDelete = m(idx,:);
% delete rows
m(idx,:) = [];

Sign in to comment.


Azzi Abdelmalek
Azzi Abdelmalek on 28 Mar 2016
Edited: Azzi Abdelmalek on 28 Mar 2016
A=rand(3,3)
idx=any(A<0.1 | A>0.9,2)
out=A(idx,:)
A(idx,:)=[]

Community Treasure Hunt

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

Start Hunting!