def draw(svg, bounds, options={})
markers = (options[:markers] || self.markers) || 5
stroke_width = options[:stroke_width]
colour = options[:theme].grid || options[:theme].marker
each_marker(markers, options[:min_value], options[:max_value], bounds[:height], options, :value_formatter) do |label, y|
svg.line(:x1 => 0, :y1 => y, :x2 => bounds[:width], :y2 => y, :style => "stroke: #{colour.to_s}; stroke-width: #{stroke_width};")
end
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