create array and assign the values to proper locations

I would like store each value and add them to the previous to create an array ...

expected result should be= [-8 0 0 0 0 0 0 8], however my output is [-8 0 0 0 0 0 0 0] seems the values does NOT store and change everytime ??

clear all; clc; 
t=16;
t_all=[8 0 0 0 0 0 0 8];
for i=1:8
    z_all=-t/2;  % I want have this number as the first element in the new array
    z_all(i)=z_all+t_all(i)
end 

z_all(1)=-t/2; z_all(2)=z_all(1)+t_all(1); z_all(3)=z_all(2)+t_all(2); z_all(4)=z_all(3)+t_all(3) and so on.. until

z_all(9)=z_all(8)+t_all(8)....

Hope anyone can help!!

[madhan ravi]

Why do you keep asking the same question multiple time? Take a piece of paper and start writing with a pencil each step and you will know why it happens.

[Ali Tawfik]

I just edited for better explanation

[Ali Tawfik]

Actually, I am trying and I am kinda understand my loop not correct, but I do not know how to initialize the new vector with a specfic number then add to previous ?

hope you guide me

[Ali Tawfik]

Also, I understand I have to learn more by trying. bymyself..So I posted the question asking not only for answer but for even suggestions, not just comments without any useful suggestions

Answer 1

[madhan ravi]

clear all; clc; 
t=16;
t_all=[8 0 0 0 0 0 0 8];
z_all = zeros(size(t_all)); % preallocate
z_all(1) = -t/2;

for ii = 2:8
    z_all(ii) = z_all(ii-1)+t_all(ii-1)
end 

z_all % I leave the rest for you to analyse the result