In Files

Parent

Gruff::Dot

Graph with dots and labels along a vertical access see: 'Creating More Effective Graphs' by Robbins

Public Instance Methods

draw() click to toggle source
# File lib/gruff/dot.rb, line 9
def draw
  @has_left_labels = true
  super

  return unless @has_data

  # Setup spacing.
  #
  spacing_factor = 1.0

  @items_width = @graph_height / @column_count.to_f
  @item_width = @items_width * spacing_factor / @norm_data.size
  @d         = @d.stroke_opacity 0.0
  height     = Array.new(@column_count, 0)
  length     = Array.new(@column_count, @graph_left)
  padding    = (@items_width * (1 - spacing_factor)) / 2

  @norm_data.each_with_index do |data_row, row_index|
    data_row[DATA_VALUES_INDEX].each_with_index do |data_point, point_index|

      x_pos        = @graph_left + (data_point * @graph_width) - (@item_width.to_f/6.0).round
      y_pos        = @graph_top + (@items_width * point_index) + padding + (@item_width.to_f/2.0).round      

      if row_index == 0
        @d           = @d.stroke(@marker_color)
        @d           = @d.stroke_width 1.0
        @d           = @d.opacity 0.1
        @d           = @d.line(@graph_left, y_pos, @graph_left + @graph_width, y_pos)
      end

      @d           = @d.fill data_row[DATA_COLOR_INDEX]
      @d           = @d.stroke('transparent')
      @d           = @d.circle(x_pos, y_pos, x_pos + (@item_width.to_f/3.0).round, y_pos)

      # Calculate center based on item_width and current row
      label_center = @graph_top + (@items_width * point_index + @items_width / 2) + padding
      draw_label(label_center, point_index)
    end

  end

  @d.draw(@base_image)
end

Protected Instance Methods

draw_label(y_offset, index) click to toggle source

Draw on the Y axis instead of the X

# File lib/gruff/dot.rb, line 96
def draw_label(y_offset, index)
  if !@labels[index].nil? && @labels_seen[index].nil?
    @d.fill             = @font_color
    @d.font             = @font if @font
    @d.stroke           = 'transparent'
    @d.font_weight      = NormalWeight
    @d.pointsize        = scale_fontsize(@marker_font_size)
    @d.gravity          = EastGravity
    @d                  = @d.annotate_scaled(@base_image,
                            1, 1,
                            -@graph_left + LABEL_MARGIN * 2.0, y_offset,
                            @labels[index], @scale)
    @labels_seen[index] = 1
  end
end
draw_line_markers() click to toggle source

Instead of base class version, draws vertical background lines and label

# File lib/gruff/dot.rb, line 56
def draw_line_markers

  return if @hide_line_markers

  @d = @d.stroke_antialias false

  # Draw horizontal line markers and annotate with numbers
  @d = @d.stroke(@marker_color)
  @d = @d.stroke_width 1
  number_of_lines = 5

  # TODO Round maximum marker value to a round number like 100, 0.1, 0.5, etc.
  increment = significant(@maximum_value.to_f / number_of_lines)
  (0..number_of_lines).each do |index|

    line_diff    = (@graph_right - @graph_left) / number_of_lines
    x            = @graph_right - (line_diff * index) - 1
    @d           = @d.line(x, @graph_bottom, x, @graph_bottom + 0.5 * LABEL_MARGIN)
    diff         = index - number_of_lines
    marker_label = diff.abs * increment

    unless @hide_line_numbers
      @d.fill      = @font_color
      @d.font      = @font if @font
      @d.stroke    = 'transparent'
      @d.pointsize = scale_fontsize(@marker_font_size)
      @d.gravity   = CenterGravity
      # TODO Center text over line
      @d           = @d.annotate_scaled( @base_image,
                        0, 0, # Width of box to draw text in
                        x, @graph_bottom + (LABEL_MARGIN * 2.0), # Coordinates of text
                        marker_label.to_s, @scale)
    end # unless
    @d = @d.stroke_antialias true
  end
end

[Validate]

Generated with the Darkfish Rdoc Generator 2.