Statistics for Machine Learning

Cosine similarity

As we will be working on this concept, it would be nice to reiterate the basics. Cosine similarity is a measure of similarity between two nonzero vectors of an inner product space that measures the cosine of the angle between them. Cosine of 0⁰ is 1 and it is less than 1 for any other angle:

Here, A_i and B_i are components of vector A and B respectively:

Example: Let us assume A = [2, 1, 0, 2, 0, 1, 1, 1], B = [2, 1, 1, 1, 1, 0, 1, 1] are the two vectors and we would like to calculate the cosine similarity:

A value of ...