How to reshape and repeat at the same time.

Hi guys, I have the following data

data= [1 3 7 9 2 5]

and I want the data to be as a matrix (2*6)

 newdata=1 1  7 7  2 2
         3 3  9 9  5 5

Please help me, and thanks in advance.

Answer 1

[Walter Roberson]

num_rows = 2;
num_copies = 2;
new_data = kron(reshape(data, num_rows, []), ones(1, num_copies));

Or less verbosely,

new_data = kron(reshape(data,2,[]),ones(1,2));

[Bahaa Algebory]

Thanks Walter, your answer is useful. Now, I want to convert this matrix to a vector as

finaldata= 1 1 3 3 7 7 9 9 2 2 5 5

Note: I will process the matrix (newdata), and at the end, I will convert this matrix to a vector.

[Walter Roberson]

kron(data, [1 1])

See also repelem if you have a newer MATLAB

[Bahaa Algebory]

Hi Walter, thanks again for your response. But actually, I want to convert the matrix to a vector. In other words, I will add a noise to the matrix and I will do other things. Then I want to convert the matrix to a vector.

the matrix is:

newdata= 1 1 7 7 2 2

           3 3 9 9 5 5

I want to convert the above matrix to the following vector

finaldata= 1 1 3 3 7 7 9 9 2 2 5 5

[Walter Roberson]

finaldata = reshape( permute(reshape(new_data, 2, 2, []), [2 1 3]), 1, [] );

[Bahaa Algebory]

Thanks Walter, your answer is awesome, and it is very useful.

Answer 2

[Roger Stafford]

newdata = reshape(repmat(reshape(data,2,[]),2,1),2,[]);

[Bahaa Algebory]

Thanks Roger, your answer is useful. Now, I want to convert this matrix to a vector as

finaldata= 1 1 3 3 7 7 9 9 2 2 5 5

Note: I will process the matrix (newdata), and at the end, I will convert this matrix to a vector.

[Roger Stafford]

It is much easier to get ‘finaldata’ directly from ‘data’:

finaldata = reshape(repmat(data,2,1),1,[]);

[Bahaa Algebory]

Thanks Roger. You are right, it is easier to get "finaldata" directly from "data". But I do not want to do this. Actually, I have qpsk data, so I want to separate them into two streams. Then, I will add a noise. At the end, I will combine these two streams. So, that is why I want to get the "finaldata" from the matrix "newdata".

    % newdata= 1 1 7 7 2 2
               3 3 9 9 5 5

I want to convert the above matrix to the following vector

finaldata= 1 1 3 3 7 7 9 9 2 2 5 5

I hope you get my point.