Computing Euclidean distance between 2 points

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I found a code computing Euclidean distance as
diff = q - p;
dist = sqrt(diff * diff');
is there any difference from the standard Euclidean distance formula, why transpose is taken?

Accepted Answer

Rik
Rik on 3 May 2022
Edited: Rik on 3 May 2022
By doing a matrix multiplication on a vector, you implicitly take the sum over all elements.
Note that this will only work if both p and q are row vectors.
q=rand(1,5);p=rand(1,5);
diff=q-p;
diff * diff' , sum(diff .* diff)
ans = 0.6624
ans = 0.6624

More Answers (1)

Bruno Luong
Bruno Luong on 3 May 2022
Edited: Bruno Luong on 3 May 2022
For a row vector d
% sum(d.^2)
is equal to
% d*d'
Example
d=randi(10,1,3)
d = 1×3
9 6 5
sum(d.^2)
ans = 142
d*d'
ans = 142

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