What's the efficient way to multiply two arrays and get sum of multiplied values in Ruby?

Question

What\'s the efficient way to multiply two arrays and get sum of multiply values in Ruby? I have two arrays in Ruby:

array_A = [1, 2, 1, 4, 5, 3, 2, 6, 5, 8, 9]
a         


        

Answer 1

I would start simple and use the Ruby matrix class:

require 'matrix'

a = Matrix.row_vector( [1, 2, 1, 4, 5, 3, 2, 6, 5, 8, 9])
b = Matrix.column_vector([3, 2, 4, 2, 5, 1, 3, 3, 7, 5, 4])

result= a * b
puts result.element(0,0)

If this turns out to be too slow, then do the exact same method but with an external math library.