# Put every 3 data points in matrix A into a separate row in matrix B.

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Curious Mind on 27 Jun 2020
Answered: KSSV on 27 Jun 2020
Hi,
I have the following column vector called A:
1
2
3
4
5
6
7
8
9
What I want is a code that will take every 3 data points in A and put it in its own separate row in a new matrix called B. After the first 3 elements or data points in A has been selected and placed in the first row in B, the code should then select the next 3 data points and place them in the 2nd row in B and so on.
e.g., the 1st row in B will be 1,2,3, & 2nd row will be 4,5,6, & 3rd row will be 7,8,9 and so on until every 3 data points in A has been selected and placed in its own row in B.
Please see the attached image.
Thank you.

KSSV on 27 Jun 2020
What have you attempted so far?
Curious Mind on 27 Jun 2020
Thanks @KSSV for your message. I have something like this in mind, B = A(1:3:end) but this will select every 3rd element. I want to select 1 through 3.
dpb on 27 Jun 2020
No, you don't really want to "select" at all...all you're doing is rearranging.
Think about how and the solution should become apparent.
One line will do the dirty...

KSSV on 27 Jun 2020
A = 1:9 ;
iwant = reshape(A,3,3)' ;

R2019b