Selecting only some rows of a matrix

2 views (last 30 days)
Hi, I have a matrix A mxn and I want to select only some of its rows satisfying this criterion: A(i,1)<=1e-03 && A(i,1)>=-1e-03 && A(i,2)<=1e-03 A(i,2)>=-1e-03 && A(i,3:end)<= 1e-03. I can't use loops.
Could you help me? Thanks

Accepted Answer

Azzi Abdelmalek
Azzi Abdelmalek on 12 Dec 2013
idx=A(:,1)<=1e-03 & A(:,1)>=-1e-03 & A(:,2)<=1e-03 & A(:,2)>=-1e-03 & all(A(:,3:end)<= 1e-03,2)
B=A(idx,:)

More Answers (2)

Simon
Simon on 12 Dec 2013
Edited: Simon on 12 Dec 2013
Hi!
So, what is "i"? Did you mean ":"? I assume ":" here.
Start by looking at the first criterion, you can write
crit1 = A(:, 1) <= 1e-3;
This will give you a logical vector. Do the same with the other criterions and combine them.
Hint: For the last criterion the function "all" is useful.

Andrei Bobrov
Andrei Bobrov on 12 Dec 2013
A(all(A(:,1:2) >= -1e-3,2) & all(A <= 1e-3,2),:)

Categories

Find more on Linear and Nonlinear Regression in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!