--- /dev/null
+
+require 'rubygems'
+require 'RMagick'
+
+=begin rdoc
+
+A library for generating small unmarked graphs (sparklines).
+
+Can be used to write an image to a file or make a web service with Rails or other Ruby CGI apps.
+
+Idea and much of the outline for the source lifted directly from {Joe Gregorio's Python Sparklines web service script}[http://bitworking.org/projects/sparklines].
+
+Requires the RMagick image library.
+
+==Authors
+
+{Dan Nugent}[mailto:nugend@gmail.com] Original port from Python Sparklines library.
+
+{Geoffrey Grosenbach}[mailto:boss@topfunky.com] -- http://nubyonrails.topfunky.com
+-- Conversion to module and further maintenance.
+
+==General Usage and Defaults
+
+To use in a script:
+
+ require 'rubygems'
+ require 'sparklines'
+ Sparklines.plot([1,25,33,46,89,90,85,77,42],
+ :type => 'discrete',
+ :height => 20)
+
+An image blob will be returned which you can print, write to STDOUT, etc.
+
+For use with Ruby on Rails, see the sparklines plugin:
+
+ http://nubyonrails.com/pages/sparklines
+
+In your view, call it like this:
+
+ <%= sparkline_tag [1,2,3,4,5,6] %>
+
+Or specify details:
+
+ <%= sparkline_tag [1,2,3,4,5,6],
+ :type => 'discrete',
+ :height => 10,
+ :upper => 80,
+ :above_color => 'green',
+ :below_color => 'blue' %>
+
+Graph types:
+
+ area
+ discrete
+ pie
+ smooth
+ bar
+ whisker
+
+General Defaults:
+
+ :type => 'smooth'
+ :height => 14px
+ :upper => 50
+ :above_color => 'red'
+ :below_color => 'grey'
+ :background_color => 'white'
+ :line_color => 'lightgrey'
+
+==License
+
+Licensed under the MIT license.
+
+=end
+class Sparklines
+
+ VERSION = '0.4.1'
+
+ @@label_margin = 5.0
+ @@pointsize = 10.0
+
+ class << self
+
+ # Does the actual plotting of the graph.
+ # Calls the appropriate subclass based on the :type argument.
+ # Defaults to 'smooth'
+ def plot(data=[], options={})
+ defaults = {
+ :type => 'smooth',
+ :height => 14,
+ :upper => 50,
+ :diameter => 20,
+ :step => 2,
+ :line_color => 'lightgrey',
+
+ :above_color => 'red',
+ :below_color => 'grey',
+ :background_color => 'white',
+ :share_color => 'red',
+ :remain_color => 'lightgrey',
+ :min_color => 'blue',
+ :max_color => 'green',
+ :last_color => 'red',
+
+ :has_min => false,
+ :has_max => false,
+ :has_last => false,
+
+ :label => nil
+ }
+
+ # HACK for HashWithIndifferentAccess
+ options_sym = Hash.new
+ options.keys.each do |key|
+ options_sym[key.to_sym] = options[key]
+ end
+
+ options_sym = defaults.merge(options_sym)
+
+ # Call the appropriate method for actual plotting.
+ sparkline = self.new(data, options_sym)
+ if %w(area bar pie smooth discrete whisker).include? options_sym[:type]
+ sparkline.send options_sym[:type]
+ else
+ sparkline.plot_error options_sym
+ end
+ end
+
+ # Writes a graph to disk with the specified filename, or "sparklines.png"
+ def plot_to_file(filename="sparklines.png", data=[], options={})
+ File.open( filename, 'wb' ) do |png|
+ png << self.plot( data, options)
+ end
+ end
+
+ end # class methods
+
+ def initialize(data=[], options={})
+ @data = Array(data)
+ @options = options
+ normalize_data
+ end
+
+ ##
+ # Creates a continuous area sparkline. Relevant options.
+ #
+ # :step - An integer that determines the distance between each point on the sparkline. Defaults to 2.
+ #
+ # :height - An integer that determines what the height of the sparkline will be. Defaults to 14
+ #
+ # :upper - An integer that determines the threshold for colorization purposes. Any value less than upper will be colored using below_color, anything above and equal to upper will use above_color. Defaults to 50.
+ #
+ # :has_min - Determines whether a dot will be drawn at the lowest value or not. Defaults to false.
+ #
+ # :has_max - Determines whether a dot will be drawn at the highest value or not. Defaults to false.
+ #
+ # :has_last - Determines whether a dot will be drawn at the last value or not. Defaults to false.
+ #
+ # :min_color - A string or color code representing the color that the dot drawn at the smallest value will be displayed as. Defaults to blue.
+ #
+ # :max_color - A string or color code representing the color that the dot drawn at the largest value will be displayed as. Defaults to green.
+ #
+ # :last_color - A string or color code representing the color that the dot drawn at the last value will be displayed as. Defaults to red.
+ #
+ # :above_color - A string or color code representing the color to draw values above or equal the upper value. Defaults to red.
+ #
+ # :below_color - A string or color code representing the color to draw values below the upper value. Defaults to gray.
+
+ def area
+
+ step = @options[:step].to_i
+ height = @options[:height].to_i
+ background_color = @options[:background_color]
+
+ create_canvas((@norm_data.size - 1) * step + 4, height, background_color)
+
+ upper = @options[:upper].to_i
+
+ has_min = @options[:has_min]
+ has_max = @options[:has_max]
+ has_last = @options[:has_last]
+
+ min_color = @options[:min_color]
+ max_color = @options[:max_color]
+ last_color = @options[:last_color]
+ below_color = @options[:below_color]
+ above_color = @options[:above_color]
+
+
+ coords = [[0,(height - 3 - upper/(101.0/(height-4)))]]
+ i=0
+ @norm_data.each do |r|
+ coords.push [(2 + i), (height - 3 - r/(101.0/(height-4)))]
+ i += step
+ end
+ coords.push [(@norm_data.size - 1) * step + 4, (height - 3 - upper/(101.0/(height-4)))]
+
+ # TODO Refactor! Should take a block and do both.
+ #
+ # Block off the bottom half of the image and draw the sparkline
+ @draw.fill(above_color)
+ @draw.define_clip_path('top') do
+ @draw.rectangle(0,0,(@norm_data.size - 1) * step + 4,(height - 3 - upper/(101.0/(height-4))))
+ end
+ @draw.clip_path('top')
+ @draw.polygon *coords.flatten
+
+ # Block off the top half of the image and draw the sparkline
+ @draw.fill(below_color)
+ @draw.define_clip_path('bottom') do
+ @draw.rectangle(0,(height - 3 - upper/(101.0/(height-4))),(@norm_data.size - 1) * step + 4,height)
+ end
+ @draw.clip_path('bottom')
+ @draw.polygon *coords.flatten
+
+ # The sparkline looks kinda nasty if either the above_color or below_color gets the center line
+ @draw.fill('black')
+ @draw.line(0,(height - 3 - upper/(101.0/(height-4))),(@norm_data.size - 1) * step + 4,(height - 3 - upper/(101.0/(height-4))))
+
+ # After the parts have been masked, we need to let the whole canvas be drawable again
+ # so a max dot can be displayed
+ @draw.define_clip_path('all') do
+ @draw.rectangle(0,0,@canvas.columns,@canvas.rows)
+ end
+ @draw.clip_path('all')
+
+ drawbox(coords[@norm_data.index(@norm_data.min)+1], 1, min_color) if has_min == true
+ drawbox(coords[@norm_data.index(@norm_data.max)+1], 1, max_color) if has_max == true
+
+ drawbox(coords[-2], 1, last_color) if has_last == true
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+ ##
+ # A bar graph.
+
+ def bar
+ step = @options[:step].to_i
+ height = @options[:height].to_f
+ background_color = @options[:background_color]
+
+ create_canvas(@norm_data.length * step + 2, height, background_color)
+
+ upper = @options[:upper].to_i
+ below_color = @options[:below_color]
+ above_color = @options[:above_color]
+
+ i = 1
+ @norm_data.each_with_index do |r, index|
+ color = (r >= upper) ? above_color : below_color
+ @draw.stroke('transparent')
+ @draw.fill(color)
+ @draw.rectangle( i, @canvas.rows,
+ i + step - 2, @canvas.rows - ( (r / @maximum_value) * @canvas.rows) )
+ i += step
+ end
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+
+ ##
+ # Creates a discretized sparkline
+ #
+ # :height - An integer that determines what the height of the sparkline will be. Defaults to 14
+ #
+ # :upper - An integer that determines the threshold for colorization purposes. Any value less than upper will be colored using below_color, anything above and equal to upper will use above_color. Defaults to 50.
+ #
+ # :above_color - A string or color code representing the color to draw values above or equal the upper value. Defaults to red.
+ #
+ # :below_color - A string or color code representing the color to draw values below the upper value. Defaults to gray.
+
+ def discrete
+
+ height = @options[:height].to_i
+ upper = @options[:upper].to_i
+ background_color = @options[:background_color]
+ step = @options[:step].to_i
+
+ create_canvas(@norm_data.size * step - 1, height, background_color)
+
+ below_color = @options[:below_color]
+ above_color = @options[:above_color]
+
+ i = 0
+ @norm_data.each do |r|
+ color = (r >= upper) ? above_color : below_color
+ @draw.stroke(color)
+ @draw.line(i, (@canvas.rows - r/(101.0/(height-4))-4).to_i,
+ i, (@canvas.rows - r/(101.0/(height-4))).to_i)
+ i += step
+ end
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+
+ ##
+ # Creates a pie-chart sparkline
+ #
+ # :diameter - An integer that determines what the size of the sparkline will be. Defaults to 20
+ #
+ # :share_color - A string or color code representing the color to draw the share of the pie represented by percent. Defaults to red.
+ #
+ # :remain_color - A string or color code representing the color to draw the pie not taken by the share color. Defaults to lightgrey.
+
+ def pie
+ diameter = @options[:diameter].to_i
+ background_color = @options[:background_color]
+
+ create_canvas(diameter, diameter, background_color)
+
+ share_color = @options[:share_color]
+ remain_color = @options[:remain_color]
+ percent = @norm_data[0]
+
+ # Adjust the radius so there's some edge left in the pie
+ r = diameter/2.0 - 2
+ @draw.fill(remain_color)
+ @draw.ellipse(r + 2, r + 2, r , r , 0, 360)
+ @draw.fill(share_color)
+
+ # Special exceptions
+ if percent == 0
+ # For 0% return blank
+ @draw.draw(@canvas)
+ return @canvas.to_blob
+ elsif percent == 100
+ # For 100% just draw a full circle
+ @draw.ellipse(r + 2, r + 2, r , r , 0, 360)
+ @draw.draw(@canvas)
+ return @canvas.to_blob
+ end
+
+ # Okay, this part is as confusing as hell, so pay attention:
+ # This line determines the horizontal portion of the point on the circle where the X-Axis
+ # should end. It's caculated by taking the center of the on-image circle and adding that
+ # to the radius multiplied by the formula for determinig the point on a unit circle that a
+ # angle corresponds to. 3.6 * percent gives us that angle, but it's in degrees, so we need to
+ # convert, hence the muliplication by Pi over 180
+ arc_end_x = r + 2 + (r * Math.cos((3.6 * percent)*(Math::PI/180)))
+
+ # The same goes for here, except it's the vertical point instead of the horizontal one
+ arc_end_y = r + 2 + (r * Math.sin((3.6 * percent)*(Math::PI/180)))
+
+ # Because the SVG path format is seriously screwy, we need to set the large-arc-flag to 1
+ # if the angle of an arc is greater than 180 degrees. I have no idea why this is, but it is.
+ percent > 50? large_arc_flag = 1: large_arc_flag = 0
+
+ # This is also confusing
+ # M tells us to move to an absolute point on the image. We're moving to the center of the pie
+ # h tells us to move to a relative point. We're moving to the right edge of the circle.
+ # A tells us to start an absolute elliptical arc. The first two values are the radii of the ellipse
+ # the third value is the x-axis-rotation (how to rotate the ellipse if we wanted to [could have some fun
+ # with randomizing that maybe), the fourth value is our large-arc-flag, the fifth is the sweep-flag,
+ # (again, confusing), the sixth and seventh values are the end point of the arc which we calculated previously
+ # More info on the SVG path string format at: http://www.w3.org/TR/SVG/paths.html
+ path = "M#{r + 2},#{r + 2} h#{r} A#{r},#{r} 0 #{large_arc_flag},1 #{arc_end_x},#{arc_end_y} z"
+ @draw.path(path)
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+
+ ##
+ # Creates a smooth sparkline.
+ #
+ # :step - An integer that determines the distance between each point on the sparkline. Defaults to 2.
+ #
+ # :height - An integer that determines what the height of the sparkline will be. Defaults to 14
+ #
+ # :has_min - Determines whether a dot will be drawn at the lowest value or not. Defaults to false.
+ #
+ # :has_max - Determines whether a dot will be drawn at the highest value or not. Defaults to false.
+ #
+ # :has_last - Determines whether a dot will be drawn at the last value or not. Defaults to false.
+ #
+ # :min_color - A string or color code representing the color that the dot drawn at the smallest value will be displayed as. Defaults to blue.
+ #
+ # :max_color - A string or color code representing the color that the dot drawn at the largest value will be displayed as. Defaults to green.
+ #
+ # :last_color - A string or color code representing the color that the dot drawn at the last value will be displayed as. Defaults to red.
+
+ def smooth
+
+ step = @options[:step].to_i
+ height = @options[:height].to_i
+ background_color = @options[:background_color]
+
+ create_canvas((@norm_data.size - 1) * step + 4, height, background_color)
+
+ min_color = @options[:min_color]
+ max_color = @options[:max_color]
+ last_color = @options[:last_color]
+ has_min = @options[:has_min]
+ has_max = @options[:has_max]
+ has_last = @options[:has_last]
+ line_color = @options[:line_color]
+
+ @draw.stroke(line_color)
+ coords = []
+ i=0
+ @norm_data.each do |r|
+ coords.push [ 2 + i, (height - 3 - r/(101.0/(height-4))) ]
+ i += step
+ end
+
+ open_ended_polyline(coords)
+
+ drawbox(coords[@norm_data.index(@norm_data.min)], 2, min_color) if has_min == true
+
+ drawbox(coords[@norm_data.index(@norm_data.max)], 2, max_color) if has_max == true
+
+ drawbox(coords[-1], 2, last_color) if has_last == true
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+
+ ##
+ # Creates a whisker sparkline to track on/off type data. There are five states:
+ # on, off, no value, exceptional on, exceptional off. On values create an up
+ # whisker and off values create a down whisker. Exceptional values may be
+ # colored differently than regular values to indicate, for example, a shut out.
+ # No value produces an empty row to indicate a tie.
+ #
+ # * results - an array of integer values between -2 and 2. -2 is exceptional
+ # down, 1 is regular down, 0 is no value, 1 is up, and 2 is exceptional up.
+ # * options - a hash that takes parameters
+ #
+ # :height - height of the sparkline
+ #
+ # :whisker_color - the color of regular whiskers; defaults to black
+ #
+ # :exception_color - the color of exceptional whiskers; defaults to red
+
+ def whisker
+
+ # step = @options[:step].to_i
+ height = @options[:height].to_i
+ background_color = @options[:background_color]
+
+ create_canvas((@data.size - 1) * 2, height, background_color)
+
+ whisker_color = @options[:whisker_color] || 'black'
+ exception_color = @options[:exception_color] || 'red'
+
+ i = 0
+ @data.each do |r|
+ color = whisker_color
+
+ if ( (r == 2 || r == -2) && exception_color )
+ color = exception_color
+ end
+
+ y_mid_point = (r >= 1) ? (@canvas.rows/2.0 - 1).ceil : (@canvas.rows/2.0).floor
+
+ y_end_point = y_mid_point
+ if ( r > 0)
+ y_end_point = 0
+ end
+
+ if ( r < 0 )
+ y_end_point = @canvas.rows
+ end
+
+ @draw.stroke( color )
+ @draw.line( i, y_mid_point, i, y_end_point )
+ i += 2
+ end
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+ ##
+ # Draw the error Sparkline.
+
+ def plot_error(options={})
+ create_canvas(40, 15, 'white')
+
+ @draw.fill('red')
+ @draw.line(0,0,40,15)
+ @draw.line(0,15,40,0)
+
+ @draw.draw(@canvas)
+ @canvas.to_blob
+ end
+
+private
+
+ def normalize_data
+ @maximum_value = @data.max
+ if @options[:type].to_s == 'pie'
+ @norm_data = @data
+ else
+ @norm_data = @data.map { |value| value = (value.to_f / @maximum_value) * 100.0 }
+ end
+ end
+
+ ##
+ # * :arr - an array of points (represented as two element arrays)
+
+ def open_ended_polyline(arr)
+ 0.upto(arr.length - 2) { |i|
+ @draw.line(arr[i][0], arr[i][1], arr[i+1][0], arr[i+1][1])
+ }
+ end
+
+ ##
+ # Create an image to draw on and a drawable to do the drawing with.
+ #
+ # TODO Refactor into smaller methods
+
+ def create_canvas(w, h, bkg_col)
+ @draw = Magick::Draw.new
+ @draw.pointsize = @@pointsize # TODO Use height
+ @canvas = Magick::Image.new(w , h) { self.background_color = bkg_col }
+
+ # Make room for label and last value
+ unless @options[:label].nil?
+ @options[:has_last] = true
+ @label_width = calculate_width(@options[:label])
+ @data_last_width = calculate_width(@data.last)
+ # HACK The 7.0 is a severe hack. Must figure out correct spacing
+ @label_and_data_last_width = @label_width + @data_last_width + @@label_margin * 7.0
+ w += @label_and_data_last_width
+ end
+
+ @canvas = Magick::Image.new(w , h) { self.background_color = bkg_col }
+ @canvas.format = "PNG"
+
+ # Draw label and last value
+ unless @options[:label].nil?
+ if ENV.has_key?('MAGICK_FONT_PATH')
+ vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
+ @font = File.exists?(vera_font_path) ? vera_font_path : nil
+ else
+ @font = nil
+ end
+
+ @draw.fill = 'black'
+ @draw.font = @font if @font
+ @draw.gravity = Magick::WestGravity
+ @draw.annotate( @canvas,
+ @label_width, 1.0,
+ w - @label_and_data_last_width + @@label_margin, h - calculate_caps_height/2.0,
+ @options[:label])
+
+ @draw.fill = 'red'
+ @draw.annotate( @canvas,
+ @data_last_width, 1.0,
+ w - @data_last_width - @@label_margin * 2.0, h - calculate_caps_height/2.0,
+ @data.last.to_s)
+ end
+ end
+
+ ##
+ # Utility to draw a coloured box
+ # Centred on pt, offset off in each direction, fill color is col
+
+ def drawbox(pt, offset, color)
+ @draw.stroke 'transparent'
+ @draw.fill(color)
+ @draw.rectangle(pt[0]-offset, pt[1]-offset, pt[0]+offset, pt[1]+offset)
+ end
+
+ def calculate_width(text)
+ @draw.get_type_metrics(@canvas, text.to_s).width
+ end
+
+ def calculate_caps_height
+ @draw.get_type_metrics(@canvas, 'X').height
+ end
+
+end
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