How to reshape matrix 2 columns by 2 columns

for example, an array like this:

1 0 2 0 2 3

5 4 4 0 1 4

4 2 2 4 2 2

1 1 0 4 3 1

How to reshape it into an array like this:

1 0

5 4

4 2

1 1

2 0

4 0

2 4

0 4

2 3

1 4

2 2

3 1

Answer 1

[Sriram Tadavarty]

Hi Ren,

Use individual columns and append them. For the sample code you provided, it can be done as below:

a = [1	0	2	0	2	3;
5	4	4	0	1	4;
4	2	2	4	2	2;
1	1	0	4	3	1];

a1 = a(:,1:2:end); % Select the odd numbered columns
a2 = a(:,2:2:end); % Select the even numbered columns
[a1(:) a2(:)] % Append them

Hope this helps.

Regards,

Sriram

[Ren Li]

hi Sriram

this is what i wanted, it works and thank you very much

[madhan ravi]

Sriram how’s this different from my answer?

[Sriram Tadavarty]

Hi Madhan,

I wasn't aware that there was another answer provided by the time i answered it. Looking at your answer now, yes, both are equivalent. Mine has some additional comments.

If i knew that this is already answered, i wouldn't have answered it at all. I think we both looked at the same time, but my answer publish went late by couple of mins.

Sorry for any trouble here. I didn't do anything intentional. I am even ok, if you wanted yours to be an accepted answer, as you mentioned early enough. My answer has just some additional comments.

Thanking you.

Regards,

Sriram

[madhan ravi]

No problem Sriram ;). By the way I think concatenate could be used instead of append I believe. Append is something which is used for adding something at the end of already existing variable/array.

Answer 2

[Walter Roberson]

cell2mat(mat2cell(YourArray, size(YourArray,1), 2*ones(1,size(YourArray,2)/2)).')

[Ren Li]

Thank you very much for the code, after spending sometime understanding it, I believe this gives even more flexibility on how to rearrange the matrix, now with this code, I can easily reshape it N columns by N columns, which in my case is exactly what I will need to do next. So again thank you so much

Answer 3

[madhan ravi]

 First = matrix(:, 1:2:end);
 Second = matrix(:, 2:2:end);
 Wanted = [First(:), Second(:)]

[Ren Li]

thank you very much

Answer 4

[Bruno Luong]

You want a reshape? Here is reshape method:

B = reshape(permute(reshape(A,size(A,1),2,[]),[1 3 2]),[],2)