double cosine ( SparseVector vec1 , SparseVector vec2 ) { double norm1 = vec1 . norm ( ) ; double norm2 = vec2 . norm ( ) ; double result = 0.0f ; if ( norm1 == 0 && norm2 == 0 ) { return result ; } else { double prod = inner_product ( vec1 , vec2 ) ; result = prod / ( norm1 * norm2 ) ; return Double . isNaN ( result ) ? 0.0f : result ; } }
Calculate the cosine value between vectors .