CODEWITHSUNDEEP
matlabmultidimensional-array
user2550888
user2550888

Reputation: 293

Delete Empty Matrices in Multidimensional Array - MATLAB

I am looking for a way to delete empty matrices within a multidimensional array in MATLAB.

For example, I have a 4-D array such as:

N = 5;
Arr = zeros(2,2,4,N);

Lets assume only N = 2 and N = 4 have values (i.e the four 2x2 matrices in N = 1, 3 and 5 are zeros), how can I create another multidimensional array ArrFin(2,2,4,2) such that

ArrFin(2,2,4,1) = Arr(2,2,4,2); 
ArrFin(2,2,4,2) = Arr(2,2,4,4);

I have tried to make the question quite general so that others can benefit from it as well but if I am not making much sense let me know.

Thanks in advance :)

Upvotes: 0

Views: 153

Answers (2)

Divakar
Divakar

Reputation: 221514

Code

%%// Create data
Arr= rand(2,2,4,5);
Arr(:,:,:,[1 3 5]) = 0;

%%// Get new reduced matrix and check for its size
ArrFin = Arr(:,:,:,find(sum(reshape(sum(Arr,3),size(Arr,3),size(Arr,4)),1)));
size_check  = size(ArrFin)

Output

size_check =

     2     2     4     2

Upvotes: 0

user2550888
user2550888

Reputation: 293

Figured out quite a neat way to do it:

ArrFin = Arr(:,:,:,any(any(any(Arr,3))));

This picks out the non zero matrices and saves them into ArrFin.

Upvotes: 2

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