Generate cell of random numbers with same size arrays

Hello!

I'd like to generate a 3x2 cell, whose arrays are all matrices 5x100 of random numbers.

I am a bit struggling with it, despite I think is quite easy to do.

Any suggestion?

Thanks

[Jan]

What have you tried so far? What are yiou struggling with?

[Riccardo Zabatta]

What I've tried so far is something derived I found on the community.

%lowercase variables are MATRICES, capitals are CELLS

%define a, matrix 18x100 of random integers
a = randi(50,18,100);
%define A, cell derived from a, where its 18 rows are splitted in three 6-rows arrays
A = mat2cell(a,[6,6,6],100);

So, this way A results to be a 3x1 cell.

But I need it to be 3x2, so I tried to define B:

%ATTEMPT 1)
%define B, cell derived from matrix a, where its "structure" is splited in six 18x50 arrays
B = mat2cell(a,([6,6,6],50),([6,6,6],50));

But this does not work bc of syntax

I solved my problem by defining, same as I did for A, a new 3x1 cell called C and then I defined my definitive cell (let's call it D):

%ATTEMPT 2)
%define a,b matrices 18x100 of random integers
a = randi(50,18,100);
b = randi(50,18,100);
%define A,B cells derived from a,b respectively.
% Where their 18 rows are splitted in three 6-rows arrays
A = mat2cell(a,[6,6,6],100); % 3x1 cell
B = mat2cell(b,[6,6,6],100); % 3x1 cell

E = [A,B];

But still I am wondering if there is a way to get success from attempt 1)

[Jan]

A a 3x2 cell with containing 5x100 matrices, a 15 x 200 random matrix is needed. Why do you create a 18x100 matrix?

Answer 1

[Jan]

Creating a large array only to split it into parts needs more RAM than creating the random matrices in parts directly:

C = cell(3, 2);
for k = 1:numel(C)
    C{k} = randi(50, 5, 100);
end

If mat2cell is required for any reasons:

a = randi(50, 15, 200);
A = mat2cell(a, [5, 5, 5], [100, 100])

Answer 2

[John D'Errico]

Simple enough.

A = rand(15,200);
B = mat2cell(A,repmat(5,3,1),repmat(100,1,2));
size(B)

ans = 1×2

3 2

size(B{1,1})

ans = 1×2

5 100

class(B{1,1})

ans = 'double'

So B is a cell array of size 3x2.

Each element of B is a regular double precision array, of size 5x100. You can put whatever you kind of random numbers you wish into the original array A.

[Riccardo Zabatta]

Thanks John, your answer works too!