def draw(svg, bounds, options={})
stroke_width = options[:stroke_width]
colour = options[:theme].grid || options[:theme].marker
unless options[:show_x] == false
y = (options[:max_value] * bounds[:height])/(options[:max_value] - options[:min_value])
svg.line(:x1 => 0, :y1 => y, :x2 => bounds[:width], :y2 => y, :style => "stroke: #{colour.to_s}; stroke-width: #{stroke_width};")
end
unless options[:show_y] == false
x = -0.5
svg.line(:x1 => x, :y1 => 0, :x2 => x, :y2 => bounds[:height], :style => "stroke: #{colour.to_s}; stroke-width: #{stroke_width};")
end
end