def minkowski(u, v)
      # TODO: Change this to a more specific, custom-made exception.
      raise ArgumentError if u.size != v.size

      u.zip(v).reduce(0) do |acc, elem|
        acc += (elem[0] - elem[1]).abs
      end
    end
def minkowski(u, v)
      # TODO: Change this to a more specific, custom-made exception.
      raise ArgumentError if u.size != v.size

      u.zip(v).reduce(0) do |acc, elem|
        acc += (elem[0] - elem[1]).abs
      end
    end
call-seq:
     minkowski(u, v) -> Numeric

 Calculate the sum of the absolute value of the differences between each
 coordinate of +u+ and +v+.

 Arguments:
 - +u+ -> An array of Numeric objects.
 - +v+ -> An array of Numeric objects.
 Returns:
 - The Minkowski (or L1) distance between +u+ and +v+.
 Raises:
 - +ArgumentError+ -> The sizes of +u+ and +v+ don't match.