Sum of Euclidean distances

Hi.

There are 5 points in 3D space: xyz=rand(5,3).

How can I quickly calculate a sum of Euclidean distances from the 1st point till the rest of points (2nd-5th)?

Thanks.

Answer 1

[David Young]

diffs = bsxfun(@minus, xyz(2:end,:), xyz(1,:));
distance = sum(sqrt(sum(diffs.^2, 2)))

Answer 2

[Grzegorz Knor]

sum((xyz(2:end,:)-repmat(xyz(1,:),size(xyz,1)-1,1)).^2,2).^0.5

or with loop;

for k=2:5
  d(k-1) = norm(xyz(1,:)-xyz(k,:));
end