how to scan a matrix row by row and save index of elements

A =
    1      2    3    4
    0.5    5    6    2
    5      3    1    3  

I have a matrix-like A, and my aim is to scan the matrix row by row and save the index of values that is greater than 2 (or any threshold). In fact, I want to have an array like this:

    H = {[3,4];[2,3];[1,2,4]}

I tried to do it like below but I don't know how I can append an elemnt to the end of array H.

If you can suggest anything faster way, I would appreciate it.

for i = 1:width(A)
    H{i} = [];
    for j = 1:height(A)
        if A(i,j) > 2
           H{i} =  % how to indicate the index of the matxis that is true for the if condition
        end
    end
end

[Matt J]

I wonder why you wouldn't simply use a sparse binarymatrix:

H=sparse(A>2);

Answer 1

[Matt J]

A = [1      2    3    4
    0.5    5    6    2
    5      3    1    3] ;

[I,J]=find(A>2);
H=accumarray(I,J,[],@(x){x.'});


H{:}

ans = 1×2

3 4

ans = 1×2

2 3

ans = 1×3

1 2 4

[ali eskandari]

Thank you @Matt J but this will return the values not the index of each.

[Matt J]

But I demonstrated it for you on your example!