Class: Gruff::Bezier

Inherits:
Base
  • Object
show all
Defined in:
lib/gruff/bezier.rb

Overview

Gruff::Bezier is a special line graph that have the bezier curve.

Here’s how to set up a Gruff::Bezier.

dataset = [
  +0.00, +0.09, +0.19, +0.29, +0.38, +0.47, +0.56, +0.64, +0.71, +0.78,
  +0.84, +0.89, +0.93, +0.96, +0.98, +0.99, +0.99, +0.99, +0.97, +0.94,
  +0.90, +0.86, +0.80, +0.74, +0.67, +0.59, +0.51, +0.42, +0.33, +0.23,
  +0.14, +0.04, -0.06, -0.16, -0.26, -0.36, -0.45, -0.53, -0.62, -0.69,
  -0.76, -0.82, -0.88, -0.92, -0.96, -0.98, -1.00, -1.00, -1.00, -0.99,
  -0.96, -0.93, -0.89, -0.84, -0.78, -0.71, -0.64, -0.56, -0.47, -0.38,
]
g = Gruff::Bezier.new
g.data 'sin', dataset
g.write('bezier.png')

Constant Summary

Constants inherited from Base

Gruff::Base::DEFAULT_MARGIN, Gruff::Base::DEFAULT_TARGET_WIDTH, Gruff::Base::LABEL_MARGIN, Gruff::Base::LEGEND_MARGIN

Instance Attribute Summary

Attributes inherited from Base

#bold_title, #bottom_margin, #center_labels_over_point, #colors, #font_color, #has_left_labels, #hide_legend, #hide_line_markers, #hide_line_numbers, #hide_title, #label_max_size, #label_stagger_height, #label_truncation_style, #labels, #left_margin, #legend_at_bottom, #legend_box_size, #legend_font_size, #legend_margin, #marker_color, #marker_font_size, #marker_shadow_color, #maximum_value, #minimum_value, #no_data_message, #right_margin, #sort, #sorted_drawing, #title, #title_font, #title_font_size, #title_margin, #top_margin, #use_data_label, #x_axis_increment, #x_axis_label, #y_axis_increment, #y_axis_label

Instance Method Summary collapse

Methods inherited from Base

#add_color, #data, #font=, #initialize, #margins=, #replace_colors, #theme=, #theme_37signals, #theme_greyscale, #theme_keynote, #theme_odeo, #theme_pastel, #theme_rails_keynote, #to_blob, #to_image, #write

Constructor Details

This class inherits a constructor from Gruff::Base

Instance Method Details

#draw ⇒ Object 



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# File 'lib/gruff/bezier.rb', line 22

def draw
  super

  return unless data_given?

  x_increment = @graph_width / (column_count - 1).to_f

  store.norm_data.each do |data_row|
    poly_points = []

    data_row[1].each_with_index do |data_point, index|
      # Use incremented x and scaled y
      new_x = @graph_left + (x_increment * index)
      new_y = @graph_top + (@graph_height - data_point * @graph_height)

      if index == 0 && RUBY_PLATFORM != 'java'
        poly_points << new_x
        poly_points << new_y
      end

      poly_points << new_x
      poly_points << new_y

      draw_label(new_x, index)
    end

    stroke_width = clip_value_if_greater_than(@columns / (store.norm_data.first[1].size * 4), 5.0)

    if RUBY_PLATFORM == 'java'
      Gruff::Renderer::Polyline.new(color: data_row.color, width: stroke_width).render(poly_points)
    else
      Gruff::Renderer::Bezier.new(color: data_row.color, width: stroke_width).render(poly_points)
    end
  end
end