How to merge matrix in a loop?

Suppose I have four matrix

A,B,C and D. These all are (mx3) matrix where m is some number.

and I have to define a number as an user input which is N.

Now I want a merge matrix such that,

for N = 1

New_matrix = [A]

for N = 2

New_matrix = [A

B

C]

for N = 3

New_matrix = [A

B

C

D

A]

for N = 4

New_matrix = [A

B

C

D

A

B

C]

and so on......

Answer 1

[David Hill]

A=randi(10,4,3)

A = 4×3

10 2 9 7 7 4 10 5 1 5 9 2

B=randi(10,5,3)

B = 5×3

8 6 1 10 1 9 6 5 9 5 8 8 10 3 3

C=randi(10,6,3)

C = 6×3

1 6 4 9 4 2 7 5 6 9 5 4 3 2 5 1 2 7

D=randi(10,7,3)

D = 7×3

5 8 3 4 9 5 5 3 9 6 7 7 4 9 3 8 5 6 7 9 9

N=2;
newMatrix=generateMatrix(A,B,C,D,N)

newMatrix = 15×3

10 2 9 7 7 4 10 5 1 5 9 2 8 6 1 10 1 9 6 5 9 5 8 8 10 3 3 1 6 4

function newMatrix=generateMatrix(A,B,C,D,N)
n=2*N-1;
s=[size(A,1),size(B,1),size(C,1),size(D,1)];
newMatrix=repmat([A;B;C;D],ceil(n/4),1);
S=sum(s*floor(n/4))+sum(s(1:mod(n,4)));
newMatrix=newMatrix(1:S,:);
end

[Akshay Sahu]

Thank you @David Hill, your algorithm worked as I want.

Answer 2

[KALYAN ACHARJYA]

% Just example
A=rand(4,3);
B=rand(4,3);
C=rand(4,3);
D=rand(4,3);
data_mat={A,B,C,D}; % Created to handle data easily
N=4 ; % Example or length of data_mat
data=cell(1,N); %Memory Pre-allocation
for i=1:N
    data{i}=horzcat(data_mat{1:i});
end 
data

data = 1×4 cell array
    {4×3 double}    {4×6 double}    {4×9 double}    {4×12 double}

You may look for cellfun also, please do the modification as per requirements.

[KALYAN ACHARJYA]

To store matrix or any other data type, cell array is much easier way to handle it.

Hope it helps!

[Akshay Sahu]

Yes, It's also correct for N=4. But N is not constant in my case. I want to change value of N according to my need.