27 Aug 2003
CS 6210: Module 3
26/31
Cosine Similarity
¡If X and Y are two n-dimensional vectors:
lX · Y = |X| |Y| cos θ
lcos θ = X · Y / |X| |Y|
l
l= 1 when identical
l= 0 when orthogonal
θ
Cos (Q,Dd) = Q · Dd / |Q| |Dd|
= (1/WqWd) Σ wq,t · wd,t
= (1/Wd) Σ wq,t · wd,t
q
d