w1 and w0 solver for linear regression in ai class

w1andw0.rb

M = 5

XS = [1,3,4,5,9]
YS = [2,5.2,6.8,8.4,14.8]
#XS = [0,1,2,3,4]
#YS = [3,6,7,8,11]

def calc_w1
  ((M * summation_of_x_and_y) - (summation_of_x * summation_of_y)) / ((M * summation_of_x_squared) - (summation_of_x * summation_of_x))
end

def calc_w0
  (summation_of_y / M) - ((calc_w1 / M) * summation_of_x)
end

def summation_of_x_and_y
  summation = []
  (0..4).each do |i|
     summation << XS[i] * YS[i]
  end
  summation.reduce(:+).to_f
end

def summation_of_x
  XS.reduce(:+).to_f
end

def summation_of_y
  YS.reduce(:+).to_f
end

def summation_of_x_squared
  total = 0
  XS.map do |x|
    total = total + x*x
  end
  total.to_f
end

puts calc_w1
puts calc_w0
puts (summation_of_y / M) - ((calc_w1 / M) * summation_of_x)
puts summation_of_y
puts summation_of_x