Sparse 3D matrix

Suppose I have a sparse matrix F of order 4 x 4. Now I want to store this sparse matrix in 3d matrix. What is the syntax for this representation. that is I want to assign A(:, :,1) = F. Since F is sparse it is showing an error. But if I assign A(:, :,1) = full(F), then it is working. But in that case F is not sparse. F consists of many zeros. Kindly tell me how to assign a sparse matrix in a 3d matrix.

[KSSV]

You need to read about sparse matrix. sparse saves only non-zero values and their respective indices. If you want to assign it into a 3D matrix, obviously you need to use full matrix. You cannot simply assign sparse to a 3D matrix. If you still insist on, you can save sparse into a cell, so that it can save your memory.

[Guillaume]

@TR RAO, You've already asked this question a day earlier. No matter how many times you asked, the answer will be the same.

[TR RAO]

Sir, Thank You Sir. Yesterday I could not understand after reading sparse matrices. Now I understood.

Answer 1

[Matt J]

You can't hold a normal Matlab 3D array in sparse form, but you can do it with my ndSparse class (Download), as long as you're mindful of the limitations.

    Afull=cat(3,eye(4),diag([14,0,0,27]));   %example
      Afull(2,3,2)=52;

    F=sparse(diag([20,0,40,50]));  %example

    >> A=ndSparse(Afull); A(:,:,1)=F,

      A(:,:,1) =

         (1,1)       20
         (3,3)       40
         (4,4)       50

      A(:,:,2) =

         (1,1)       14
         (2,3)       52
         (4,4)       27

    >> whos A Afull

    Name       Size             Bytes  Class       Attributes

    A          4x4x2              160  ndSparse              
    Afull      4x4x2              256  double