class Scruffy::Layers::Box

Scruffy::Layers::Box

Author

Brasten Sager

Date

August 6th, 2006

Standard bar graph.

Public Instance Methods

draw(svg, coords, options = {}) click to toggle source

Draw box plot.

# File lib/scruffy/layers/box.rb, line 11
def draw(svg, coords, options = {})
  coords.each_with_index do |coord,idx|
    x, y, bar_height = (coord.first), coord.last, 1#(height - coord.last)
    
      valh = max_value + min_value * -1 #value_height
      maxh = max_value * height / valh #positive area height
      minh = min_value * height / valh #negative area height
      #puts "height = #{height} and max_value = #{max_value} and min_value = #{min_value} and y = #{y} and point = #{points[idx]}"
      
      #if points[idx] > 0
      #  bar_height = points[idx]*maxh/max_value
      #else
      #  bar_height = points[idx]*minh/min_value
      #end
    
    #puts " y = #{y} and point = #{points[idx]}"  
    #svg.g(:transform => "translate(-#{relative(0.5)}, -#{relative(0.5)})") {
    #  svg.rect( :x => x, :y => y, :width => @bar_width + relative(1), :height => bar_height + relative(1), 
    #            :style => "fill: black; fill-opacity: 0.15; stroke: none;" )
    #  svg.rect( :x => x+relative(0.5), :y => y+relative(2), :width => @bar_width + relative(1), :height => bar_height - relative(0.5), 
    #            :style => "fill: black; fill-opacity: 0.15; stroke: none;" )
    #
    #}
    
    svg.line(:x1=>x+@bar_width/2,:x2=>x+@bar_width/2,:y1=>y[0],:y2=>y[4], :style => "stroke:#{(outline.to_s || options[:theme].marker || 'white').to_s}; stroke-width:1")
    svg.line(:x1=>x+@bar_width/4,:x2=>x+@bar_width/4*3,:y1=>y[0],:y2=>y[0], :style => "stroke:#{(outline.to_s || options[:theme].marker || 'white').to_s}; stroke-width:1")
    svg.line(:x1=>x+@bar_width/4,:x2=>x+@bar_width/4*3,:y1=>y[4],:y2=>y[4], :style => "stroke:#{(outline.to_s || options[:theme].marker || 'white').to_s}; stroke-width:1")
    svg.rect( :x => x, :y => y[1], :width => @bar_width, :height => (y[1]-y[3])*-1, 
              :fill => color.to_s, 'style' => "opacity: #{opacity}; stroke:#{(outline.to_s || options[:theme].marker || 'white').to_s}; stroke-width:1;" )
    svg.line(:x1=>x,:x2=>x+@bar_width,:y1=>y[2],:y2=>y[2], :style => "stroke:#{(outline.to_s || options[:theme].marker || 'white').to_s}; stroke-width:1")
    #svg.rect( :x => x, :y => y, :width => @bar_width, :height => bar_height, 
    #          :fill => color.to_s, 'style' => "opacity: #{opacity}; stroke: none;" )
  end
end

Protected Instance Methods

generate_coordinates(options = {}) click to toggle source

Due to the size of the bar graph, X-axis coords must be squeezed so that the bars do not hang off the ends of the graph.

Unfortunately this just mean that bar-graphs and most other graphs end up on different points. Maybe adding a padding to the coordinates should be a graph-wide thing?

Update : x-axis coords for lines and area charts should now line up with the center of bar charts.

# File lib/scruffy/layers/box.rb, line 96
def generate_coordinates(options = {})
  @bar_width = (width / points.size) * 0.9
  options[:point_distance] = (width - (width / points.size)) / (points.size - 1).to_f

  #TODO more array work with index, try to rework to be accepting of hashes
  coords = (0...points.size).map do |idx| 
    x_coord = (options[:point_distance] * idx) + (width / points.size * 0.5) - (@bar_width * 0.5)
    y_coords = []
    points[idx].each do |point| 
      relative_percent = ((point == min_value) ? 0 : ((point - min_value) / (max_value - min_value).to_f))
      y_coord = (height - (height * relative_percent))
      y_coords << y_coord
    end
    [x_coord, y_coords]
  end
  coords
end