def initialize(options={})
      @id = rand(8 ** 8)
      @format_code = "General"
      @delete = @label_rotation = 0
      @scaling = Scaling.new(:orientation=>:minMax)
      @title = @color = nil
      self.ax_pos = :b
      self.tick_lbl_pos = :nextTo
      self.format_code = "General"
      self.crosses = :autoZero
      self.gridlines = true
      parse_options options
    end
Creates an Axis object
@option options [Axis] cross_axis the perpendicular axis
@option options [Symbol] ax_pos
@option options [Symbol] crosses
@option options [Symbol] tick_lbl_pos
@raise [ArgumentError] If axi_id or cross_ax are not unsigned integers