# How to find unique matrix from given array and corresponding indexes?

1 view (last 30 days)
Triveni on 28 Aug 2021
Commented: Triveni on 1 Sep 2021
I have
A
A(:,:,1) =
Columns 1 through 2
20 20.05
20.05 20
19.95 20
Column 3
19.95
19.95
20.05
A(:,:,2) =
Columns 1 through 2
20 20.05
20.05 20
19.95 20
Column 3
19.95
19.95
20.05
A(:,:,3) =
Columns 1 through 2
20.05 20
20.05 20
19.95 20
Column 3
19.95
19.95
20.05
>> unique(A)
ans =
19.95
20
20.05
But i need to find out unique matrices and corresponding indexes
B
B(:,:,1) =
Columns 1 through 2
20 20.05
20.05 20
19.95 20
Column 3
19.95
19.95
20.05
B(:,:,2) =
Columns 1 through 2
20.05 20
20.05 20
19.95 20
Column 3
19.95
19.95
20.05
>> index = [1,3]
index =
1 3
In this format B and index.

Chunru on 28 Aug 2021
A(:,:,1) = [ 20 20.05 19.95
20.05 20 19.95
19.95 20 20.05];
A(:,:,2) = [ 20 20.05 19.95
20.05 20 19.95
19.95 20 20.05];
A(:,:,3) = [ 20.05 20 19.95
20.05 20 19.95
19.95 20 20.05];
% Reshape the matrix and find unique along each row
[uA, iA] = unique(reshape(A, [], size(A,3))', 'rows');
B = reshape(uA', size(A,1), size(A,2), [])
B =
B(:,:,1) = 20.0000 20.0500 19.9500 20.0500 20.0000 19.9500 19.9500 20.0000 20.0500 B(:,:,2) = 20.0500 20.0000 19.9500 20.0500 20.0000 19.9500 19.9500 20.0000 20.0500
iA'
ans = 1×2
1 3
Triveni on 1 Sep 2021
Thanks for your answer. It is also working for m*n*i size means A(m,n,1:i)) array.

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