how to find value in the matrix using index?

2 views (last 30 days)
Chang seok Ma
Chang seok Ma on 16 Nov 2021
Answered: KSSV on 16 Nov 2021
Hello,
I am wondering if I can find value using index.
For example, given matrix A, I would like to get third value of the first row and the second value from the second row.
I want to get 30 from the first row and 50 from the second row.
A = [10 20 30 ; 40 50 60];
B = [3;2]
Is there any way I could do this?
Thank you

Accepted Answer

KSSV
KSSV on 16 Nov 2021
Read about MATLAB matrix indexing. If A is a matrix, you can extract (i,j) element using A(i,j).
Also have a look on ind2sub and sub2ind. As you know sub indices here, convert them into global indices using sub2ind and then extract.
A = [10 20 30 ; 40 50 60];
B = [3;2] ;
idx = sub2ind(size(A),[1;2],B)
idx = 2×1
5 4
A(idx)
ans = 2×1
30 50

Community Treasure Hunt

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

Start Hunting!