Divide a big matrix into submatrices or cell

Hello all!

I want to save some of my big matrix elements into a cell array, with the main purpose of dividing them into sub matrices. The cell must contains only some numbers of the big matrix (those who belongs to one of the winning classes). For example if I have 100 classes in total and 4 winning classes I want my new matrices inside the cell containing only elements from the four winning classes. In my current code I have a problem using the end+1 command, getting an error Index exceeds array bounds. Do you have any suggestion how could I fix it?

Here follows my code:

CellArray={};

for i=1:length(Matrix)

for j=1:1:length(WinningClass)

if Matrix(i,5) == WinningClass(j,1)

CellArray{j}(end+1,1:4)= Matrix(i,1:4);

end

end

end

Answer 1

[KSSV]

Refer here: https://in.mathworks.com/matlabcentral/answers/362262-i-have-a-32-32-matrix-i-want-to-take-mean-of-each-4-4-so-that-the-matrix-is-reduced-to-8-8-array#answer_286773

[Michail Isaakidis]

Solved, it just need an empty cell array declaration on top