# how to get adress position inside vector

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alize beemiel on 12 Mar 2022
Answered: Jan on 12 Mar 2022
hi!
i have this vector
i need to some value of eld in a vector gravlo just in right position given in vector adress
but matlab say Subscript indices must either be real positive integers or logicals.
can someone help me how to fix it
gravlo=zeros(1,100);
eld =[ 0
-1.7222
0
7.0000
0
-1.7778
0
6.8889
0
-1.7778
0
7.0000
0
-1.7222
0
7.1111];
3
0
2
0
1
31
32
61
62
63
64
65
66
33
34 ];
Jan on 12 Mar 2022
Edited: Jan on 12 Mar 2022
A simplified version of your code:
gravlo = zeros(427,1);
for iel=1:5
g = G(:,iel);
m = (g ~= 0);
gravlo(g(m)) = gravlo(g(m)) - eld(m) * 20;
end
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alize beemiel on 12 Mar 2022
oh !!!
thank you Sir,
its very nice and its work with a simply code
thanks very much Sir,

Jan on 12 Mar 2022
Copied from my comment as an answer:
gravlo = zeros(427,1);
for iel = 1:5
g = G(:, iel);
m = (g ~= 0);
gravlo(g(m)) = gravlo(g(m)) - eld(m) * 20;
end