Find a pair of elements in a 3d matrix

I have a 512*512*2 matrix. If A is the matrix then I want to find the pair of elements A(:,:,1) and A(:,:,2) that are equal to a specific pair. For example I want to check if the A(1,1,1) and A(1,1,2) are equal to (0,0) and if so to keep the position (1,1). Is there a way to do so?

Answer 1

[Thorsten]

Logical index:

 idx = A(:,:,1) == 0 & A(:,:,2) == 0;

if you prefer a single index, you can use

 idx2 = find(idx);

if you prefer multiple subscripts as index, you can use

[ind_i, ind_j] = ind2sub(size(A), idx2);

[Efstathios Kontolatis]

Thanks a lot

Answer 2

[Giovanni Mottola]

Note: if it's 512*512*2 (three dimensional), it's called tensor, not matrix.

A way to do what you require would be to first define the two values you're looking for:

val1=0;
val2=0;

Then call:

[row, col]=find(A(:, :, 1)==val1 & A(:, :, 2)==val2)

Example with a smaller matrix: let

A(:,:,1) =
     4     0     5     0     3
     1     4     0     0    10
     2     5     8    10     3
     7     8     4     2     0
     7     1     2    10     6

A(:,:,2) =
     6    10     2     3     2
     9     9     5     5     7
     2     7     1     0    10
     8     2     9     3     6
     3     0    10     5     2

The pair we're looking for is, say, val1=4 and val2=9. Using the command above, we get

row =
     2
     4

col =
     2
     3

which can be easily checked.