def to_a
      if dimension == 0
        force
      else
        n = shape.last
        ( 0 ... n ).collect { |i| element( i ).to_a }
      end
    end
def to_a
      if dimension == 0
        force
      else
        n = shape.last
        ( 0 ... n ).collect { |i| element( i ).to_a }
      end
    end
Convert to Ruby array of objects

 Perform pending computations and convert native array to Ruby array of
 objects.

 @return [Array<Object>] Array of objects.