Index array of every element in MATLAB?

Question

This might be a basic question.

To find out the maximum value and its index in array in MATLAB, I have used this code:

A = [1 2 3; 4 5 6; 7 8 9]

[val, idx] = max(A, [], 2);

Now, how can I find the index array of all the element (not finding maximum)?

YOu create your list of indices and use setdiff to remove the maximum value index. Give an example to get apt help/ advice. — Siva Srinivas Kolukula, Mar 01 '19 at 03:39
I think the max value index example above is causing confusion, I just want to get the index array of any 2D matrix. — ShadowWarrior, Mar 01 '19 at 03:46
What is the expected result - the "index array" - for your example `A`? — HansHirse, Mar 01 '19 at 05:29
Are you asking how to generate an array with an index to each element of `A`? That would simply be `1:numel(A)`. If you're asking for something different I suggest you [edit] your question to clarify exactly what you want. Adding the expected result for your example case would be very useful. — Cris Luengo, Mar 01 '19 at 07:54

score 0 · Answer 1 · answered Mar 01 '19 at 04:02

0

May be you are talking bout subindices and global indices. Read about sub2ind and ind2sub. Check the below demo:

A = [1 2 3; 4 5 6; 7 8 9] ;

[m,n] = size(A) ;

% sub indices 
[J,I] = meshgrid(1:m,1:n) ;
% global indices 
idx = sub2ind(size(A),I,J)

answered Mar 01 '19 at 04:02

1 Answers1