sum within the elements of a vector

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pavlos
pavlos am 29 Feb. 2012
Hello,
Suppose you have the following 1xn vector:
v=[(1,1),(1,2),...,(1,n)]
How the sum of the elements (each other) is calculated?
For example,
The sum of first element with the others
{[(1,1)+(1,2)} {(1,1)+(1,3)} {(1,1)+(1,4)} . . . {(1,1)+(1,n)}
The sum of second element with the others
{(1,2)+(1,3)} {(1,3)+(1,4)} . . . {(1,2)+(1,n)}
and so on.
The sum {(1,1)+(1,2)} is the same with the {(1,2)+(1,1)} and should only considered once.
Also the sum of an element with itself, shouldn`t be taken into account.
Thank you.
Best,
Pavlos

Akzeptierte Antwort

Oleg Komarov
Oleg Komarov am 29 Feb. 2012
v = 1:10;
out = bsxfun(@plus,v,v');
EDIT make diagonal elements = 0
[r,c] = size(out);
out(1:r+1:r*c) = 0;
  1 Kommentar
pavlos
pavlos am 29 Feb. 2012
Thank you for your response.
My mistake: The sum between {(1,1)+(1,2)} and {(1,2)+(1,1)} should be considered,
while the sum of an element with itself should not .
That means that only the main diagonal of the matrix has zeros.
Any help please?
Thank you.
Best,
Pavlos

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Weitere Antworten (1)

Sean de Wolski
Sean de Wolski am 29 Feb. 2012
Edit
x = 1:5;
M = bsxfun(@plus,x',x);
M(1:size(M,1)+1:end) = 0;
  1 Kommentar
pavlos
pavlos am 29 Feb. 2012
That worked fine.
Thank you.
Best,
Pavlos

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