def initialize_ivars
      # Internal for calculations
      @raw_columns = 800.0
      @raw_rows = 800.0 * (@rows/@columns)
      @column_count = 0
      @data = Array.new
      @marker_count = nil
      @maximum_value = @minimum_value = nil
      @has_data = false
      @increment = nil
      @labels = Hash.new
      @label_formatting = nil
      @labels_seen = Hash.new
      @sort = false
      @sorted_drawing = false
      @title = nil
      @title_font = nil

      @scale = @columns / @raw_columns

      vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
      @font = File.exist?(vera_font_path) ? vera_font_path : nil
      @bold_title = true

      @marker_font_size = 21.0
      @legend_font_size = 20.0
      @title_font_size = 36.0

      @top_margin = @bottom_margin = @left_margin = @right_margin = DEFAULT_MARGIN
      @legend_margin = LEGEND_MARGIN
      @title_margin = TITLE_MARGIN

      @legend_box_size = 20.0

      @no_data_message = 'No Data'

      @hide_line_markers = @hide_legend = @hide_title = @hide_line_numbers = @legend_at_bottom = @show_labels_for_bar_values = false
      @center_labels_over_point = true
      @has_left_labels = false
      @label_stagger_height = 0
      @label_max_size = 0
      @label_truncation_style = :absolute

      @additional_line_values = []
      @additional_line_colors = []
      @theme_options = {}

      @use_data_label = false
      @x_axis_increment = nil
      @x_axis_label = @y_axis_label = nil
      @y_axis_increment = nil
      @stacked = nil
      @norm_data = nil
    end
def initialize_ivars
      # Internal for calculations
      @raw_columns = 800.0
      @raw_rows = 800.0 * (@rows/@columns)
      @column_count = 0
      @data = Array.new
      @marker_count = nil
      @maximum_value = @minimum_value = nil
      @has_data = false
      @increment = nil
      @labels = Hash.new
      @label_formatting = nil
      @labels_seen = Hash.new
      @sort = false
      @sorted_drawing = false
      @title = nil
      @title_font = nil

      @scale = @columns / @raw_columns

      vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
      @font = File.exist?(vera_font_path) ? vera_font_path : nil
      @bold_title = true

      @marker_font_size = 21.0
      @legend_font_size = 20.0
      @title_font_size = 36.0

      @top_margin = @bottom_margin = @left_margin = @right_margin = DEFAULT_MARGIN
      @legend_margin = LEGEND_MARGIN
      @title_margin = TITLE_MARGIN

      @legend_box_size = 20.0

      @no_data_message = 'No Data'

      @hide_line_markers = @hide_legend = @hide_title = @hide_line_numbers = @legend_at_bottom = @show_labels_for_bar_values = false
      @center_labels_over_point = true
      @has_left_labels = false
      @label_stagger_height = 0
      @label_max_size = 0
      @label_truncation_style = :absolute

      @additional_line_values = []
      @additional_line_colors = []
      @theme_options = {}

      @use_data_label = false
      @x_axis_increment = nil
      @x_axis_label = @y_axis_label = nil
      @y_axis_increment = nil
      @stacked = nil
      @norm_data = nil
    end
If one numerical argument is given, the graph is drawn at 4/3 ratio
 according to the given width (800 results in 800x600, 400 gives 400x300,
 etc.).

 Or, send a geometry string for other ratios ('800x400', '400x225').

 Looks for Bitstream Vera as the default font. Expects an environment var
 of MAGICK_FONT_PATH to be set. (Uses RMagick's default font otherwise.)
 Set instance variables for this object.

 Subclasses can override this, call super, then set values separately.

 This makes it possible to set defaults in a subclass but still allow
 developers to change this values in their program.