How to check if a 3d matrix has any 2D submatrix with non zero elements?

Hi all,

I have a 3D matrixnd I need to check if it has any sub 2D matrix with non zero elements.

a(:,:,1) =

       0     0
       0     0

a(:,:,2) =

       1     0
       0     0

the results should be

[0 1].

Thanks

cheers

Answer 1

[Sean de Wolski]

pagesWithNonZeros = squeeze(any(any(x,1),2))

You can pass dim into any to test if there are any nonzero elements in that dimension.

Answer 2

[Hugo]

You can just do

 [any(any(a(:,:,1)>0)),any(any(a(:,:,2)>0))]

or just shorter

 nonzero2D=@(a,k)any(any(a(:,:,k)>0))

 [nonzero2D(a,1), nonzero2D(a,2)]

Is that what you want?

[pietro]

It's not a general solution.