how to find value in the matrix using index?

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

Answer 1

[KSSV]

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

Answer 2

[Cris LaPierre]

See Ch 5 of MATLAB Onramp.