# How to sequentially generate a vector from loop?

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Ani Asoyan on 22 Jan 2023
Commented: Dyuman Joshi on 22 Jan 2023
Hi everyone!
I have a vector A, which I cut in a loop and take the first elements like this
A = [ 1 2 3 4 5 6 7]'
for k=1:7
A_{k} = A(1:k)
end
I want to generate a vector B which can put a subset of A (let's say the first 2 elements (A_{2}')) together with the last element of every generated vector from my loop. Basically B should be like this
B = [A_{2}' A_{3}(3) A_{4}(4) A_{5}(5) A_{6}(6) A_{7}(7)]'
How can I make this vector B easier to write for bigger k's (for example write it like a loop) ?
Thank you so much!
##### 3 CommentsShow 1 older commentHide 1 older comment
Ani Asoyan on 22 Jan 2023
With this loop it's same, but if there's another function in the loop, it's not the same. I just want to create a vector B, which contains first 2 elements of A and every time it adds the last element of a for loop
Dyuman Joshi on 22 Jan 2023
"but if there's another function in the loop"
For example?
"I just want to create a vector B, which contains first 2 elements of A and every time it adds the last element of a for loop"
Give another example, as it is not clear from the one you gave.

Sargondjani on 22 Jan 2023
s=2
for k=1:7
A_{k} = A(1:k);
if k==s
B = [A_{2}']
elseif k>s
B = [B' A_{k}(k)]'
end
end
Try to get the details right yourself.