How to measure the similarity of two data

Question

I am measuring the similarity of two data with same size is 20. That is

A=[0.915450999999999    0.908220499999997   0.900374999999996   0.890547499999996   0.88         


        

Answer 1

As suggested here, you could use cosine similarity, which finds the angle between two vectors. Similar vectors have a value close to 1 and dissimilar vectors have a value close to 0.

function d = cosSimilarity(u, v)
    d = dot(u,v)/(norm(u)*norm(v));
end