lib/sparklines.rb in sparklines-0.4.1 vs lib/sparklines.rb in sparklines-0.4.2

@@ -72,11 +72,11 @@
 Licensed under the MIT license.
 
 =end
 class Sparklines
 
-  VERSION = '0.4.1'
+  VERSION = '0.4.2'
 
   @@label_margin = 5.0
   @@pointsize = 10.0
 
   class << self
@@ -99,14 +99,16 @@
         :share_color => 'red',
         :remain_color => 'lightgrey',
         :min_color => 'blue',
         :max_color => 'green',	
         :last_color => 'red',                
+        :std_dev_color => '#efefef',
 
         :has_min => false,
         :has_max => false,
         :has_last => false,
+        :has_std_dev => false,
 
         :label => nil
       }
 
       # HACK for HashWithIndifferentAccess
@@ -142,41 +144,41 @@
   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.
+  #   :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
+    step = @options[:step].to_f
+    height = @options[:height].to_f
     background_color = @options[:background_color]
     
     create_canvas((@norm_data.size - 1) * step + 4, height, background_color)
 
-    upper = @options[:upper].to_i
+    upper = @options[:upper].to_f
 
     has_min = @options[:has_min]
     has_max = @options[:has_max]
     has_last = @options[:has_last]
 
@@ -201,19 +203,19 @@
     @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
+    @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
+    @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))))
 
@@ -235,17 +237,17 @@
 
   ##
   # A bar graph.
 
   def bar
-    step = @options[:step].to_i
+    step = @options[:step].to_f
     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
+    upper = @options[:upper].to_f
     below_color = @options[:below_color]
     above_color = @options[:above_color]
 
     i = 1
     @norm_data.each_with_index do |r, index|
@@ -263,36 +265,41 @@
 
 
   ##
   # Creates a discretized sparkline
   #
-  # :height - An integer that determines what the height of the sparkline will be.  Defaults to 14
+  #   :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.
+  #   :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.
+  #   :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.
+  #   :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
+    height = @options[:height].to_f
+    upper = @options[:upper].to_f
     background_color = @options[:background_color]
-    step = @options[:step].to_i
+    step = @options[:step].to_f
+
+    width = @norm_data.size * step - 1
         
-    create_canvas(@norm_data.size * step - 1, height, background_color)
+    create_canvas(width, height, background_color)
     
     below_color = @options[:below_color]
     above_color = @options[:above_color]
+    std_dev_color = @options[:std_dev_color]
 
+    drawstddevbox(width,height,std_dev_color) if @options[:has_std_dev] == true
+
     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)
+    	@draw.line(i, (@canvas.rows - r/(101.0/(height-4))-4).to_f,
+    	          i, (@canvas.rows - r/(101.0/(height-4))).to_f)
     	i += step
     end
 
     @draw.draw(@canvas)
     @canvas.to_blob
@@ -300,18 +307,18 @@
 
 
   ##
   # Creates a pie-chart sparkline
   #
-  # :diameter - An integer that determines what the size of the sparkline will be.  Defaults to 20
+  #   :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.
+  #   :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.
+  #   :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
+    diameter = @options[:diameter].to_f
     background_color = @options[:background_color]
 
     create_canvas(diameter, diameter, background_color)
     
     share_color = @options[:share_color]
@@ -368,41 +375,51 @@
 
 
   ##
   # Creates a smooth sparkline.
   #
-  # :step - An integer that determines the distance between each point on the sparkline.  Defaults to 2.
+  #   :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
+  #   :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_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_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.
+  #   :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.
+  #   :has_std_dev - Determines whether there will be a standard deviation bar behind the smooth graph or not. Defaults to false.
   #
-  # :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.
+  #   :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.
   #
-  # :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.
+  #   :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.
+  #
+  #   :std_dev_color - A string or color code representing the color that the standard deviation bar behind the smooth graph will be displayed as. Defaults to #efefef
 
   def smooth
 
-    step = @options[:step].to_i
-    height = @options[:height].to_i
+    step = @options[:step].to_f
+    height = @options[:height].to_f
     background_color = @options[:background_color]
 
-    create_canvas((@norm_data.size - 1) * step + 4, height, background_color)
+    width = (@norm_data.size - 1) * step + 4
+
+    create_canvas(width, 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]
+    has_std_dev = @options[:has_std_dev]
+    std_dev_color = @options[:std_dev_color]
+    
+    drawstddevbox(width,height,std_dev_color) if has_std_dev == true
 
     @draw.stroke(line_color)
     coords = []
     i=0
     @norm_data.each do |r|
@@ -432,20 +449,20 @@
   # 
   # * 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
+  #   :height - height of the sparkline
   #
-  # :whisker_color - the color of regular whiskers; defaults to black
+  #   :whisker_color - the color of regular whiskers; defaults to black
   #
-  # :exception_color - the color of exceptional whiskers; defaults to red
+  #   :exception_color - the color of exceptional whiskers; defaults to red
   
   def whisker
 
-    # step = @options[:step].to_i
-    height = @options[:height].to_i
+    # step = @options[:step].to_f
+    height = @options[:height].to_f
     background_color = @options[:background_color]
 
     create_canvas((@data.size - 1) * 2, height, background_color)
     
     whisker_color = @options[:whisker_color] || 'black'
@@ -503,11 +520,11 @@
       @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)
+  #   :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])
     }
@@ -519,10 +536,11 @@
   # TODO Refactor into smaller methods
 
   def create_canvas(w, h, bkg_col)
     @draw = Magick::Draw.new
     @draw.pointsize = @@pointsize # TODO Use height
+    @draw.pointsize = @options[:font_size] if @options.has_key?(:font_size)
     @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
@@ -542,10 +560,11 @@
         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
+      @font = @options[:font] if @options.has_key?(:font)
 
       @draw.fill = 'black'
       @draw.font = @font if @font
       @draw.gravity = Magick::WestGravity
       @draw.annotate( @canvas, 
@@ -569,14 +588,56 @@
     @draw.stroke 'transparent'
     @draw.fill(color)
     @draw.rectangle(pt[0]-offset, pt[1]-offset, pt[0]+offset, pt[1]+offset)
   end
 
+  ##
+  # Utility to draw the standard deviation box
+  #
+  def drawstddevbox(width,height,color)
+    mid=@norm_data.inject(0) {|sum,v| sum+=v}/@norm_data.size
+    std_dev = standard_deviation(@norm_data)/100*height
+    @draw.stroke 'transparent'
+    @draw.fill(color)
+    @draw.rectangle(0, mid-std_dev, width, mid+std_dev)
+  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
 
+  ##
+  # Calculation helper for standard deviation.
+  #
+  # Thanks to Warren Seen
+  # http://warrenseen.com/blog/2006/03/13/how-to-calculate-standard-deviation/
+  def variance(population)
+    n = 0
+    mean = 0.0
+    s = 0.0
+    population.each { |x|
+      n = n + 1
+      delta = x - mean
+      mean = mean + (delta / n)
+      s = s + delta * (x - mean)
+    }
+    # if you want to calculate std deviation
+    # of a sample change this to "s / (n-1)"
+    return s / n
+  end
+
+  ##
+  # Calculate the standard deviation of a population
+  #
+  #   accepts: an array, the population
+  #   returns: the standard deviation
+  def standard_deviation(population)
+    Math.sqrt(variance(population))
+  end
+
+
 end
+