How to reshape a matrix (something that can't be done with reshape function)

Let's say I have a matrix A:

A = [1 4 7 10; 2 5 8 11; 3 6 9 12]

A =

1 4 7 10

2 5 8 11

3 6 9 12

and B = reshape(A,6,2) will return:

B =

1 7

2 8

3 9

4 10

5 11

6 12

But I'm wondering if there is any way to rearrange this matrix into something that looks like this:

B =

1 4

2 5

3 6

7 10

8 11

9 12

I'd like to know an easier way than doing:

B = [A(:,[1 2]) ; A(:,[3 4])]

Thank you in advance!

Answer 1

[Stephen23]

A = [1,4,7,10;2,5,8,11;3,6,9,12]

A = 3×4

1 4 7 10 2 5 8 11 3 6 9 12

nmc = 2; % output number of columns
nmr = 3; % output number of rows per "group"
B = reshape(permute(reshape(A,nmr,nmc,[]),[1,3,2]),[],nmc)

B = 6×2

1 4 2 5 3 6 7 10 8 11 9 12

[Walter Roberson]

Which is to say that it can be done but it is by no means "easier" than extracting the two halves.

[Kenta Watanabe]

Thanks a lot! I didn't expect to get an answer this fast.

But I also understood that there may not be an easy way to do this. Thanks though!