# File lib/bio/graphics/glyph.rb, line 534
  def self.gradient(gradient)
    type, color = case gradient
    when :red_white_h
      [:linear, "red"]
    when :green_white_h
      [:linear, "green"]
    when :blue_white_h
      [:linear, "blue"]
    when :yellow_white_h
      [:linear, "yellow"]
    when :red_white_radial
      [:radial, "red"]
    when :green_white_radial
      [:radial, "green"]
    when :blue_white_radial
      [:radial, "blue"]
    when :yellow_white_radial
      [:radial, "yellow"]
    end
    
    case type
    when :linear
            {:type => :linear, 
       :id => gradient, 
       :x1 => 0, :y1 => 0, 
       :x2 => 0, :y2 => 100, 
       :stops => [
         {
          :color => color, 
          :offset => 0, 
          :opacity=> 1
          },
          {
           :color => "white", 
           :offset => 100, 
           :opacity=> 1 
           }
          ]
        }
    when :radial
      {
       :type => :radial, 
       :id => gradient, 
       :cx => 50, :cy => 50, 
       :r => 50, :fx => 50, :fy => 50, 
       :stops => [ 
         {:offset => 0, 
          :color => "white", 
          :opacity => 0
          },  
          {
          :offset => 100, 
          :color => color, 
          :opacity => 1
          }
        ]
      }
    end
    
  end