def initialize_ivars
@raw_columns = 800.0
@raw_rows = 800.0 * (@rows/@columns)
@column_count = 0
@marker_count = nil
@maximum_value = @minimum_value = nil
@has_data = false
@data = Array.new
@labels = Hash.new
@labels_seen = Hash.new
@sort = true
@title = nil
@scale = @columns / @raw_columns
vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
@font = File.exists?(vera_font_path) ? vera_font_path : nil
@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 = false
@center_labels_over_point = true
@has_left_labels = false
@additional_line_values = []
@additional_line_colors = []
@theme_options = {}
@x_axis_label = @y_axis_label = nil
@y_axis_increment = nil
@stacked = nil
@norm_data = nil
end