Cosine similarity is a measure of similarity between two vectors of an inner product space that measures the cosine of the angle between them. The cosine of 0° is 1, and it is less than 1 for any other angle. It is defined as follows:
Given two vectors A and B with the same size, calculate the cosine similarity. Return 2.0000 if cosine similarity is invalid (for example A =  and B = ).
A B Result
[1, 2, 3] [2, 3, 4] 0.9926
  2.0000