1 # Selectricity: Voting Machinery for the Masses
2 # Copyright (C) 2007, 2008 Benjamin Mako Hill <mako@atdot.cc>
3 # Copyright (C) 2007 Massachusetts Institute of Technology
5 # This program is free software. Please see the COPYING file for
9 class GraphController < ApplicationController
12 COLORS = ['#74CE00', '#005CD9', '#DC0D13', '#131313', '#A214A4', '#EFF80E',
13 '#90E5E6', '#F58313', '#437D3D', '#0E026C']
14 BACKGROUND_COLORS = ['#74CE00', '#FFFFFF'] #for green and white background
16 def initialize(options)
17 size = options[:size] ? options[:size] : "400x300" #allow custom sizing
18 @graph = options[:graph_type].new(size)
20 @graph.no_data_message = "No Voters"
22 @graph.theme = { :colors => COLORS,
23 :background_colors => ['#e5e5e5', '#FFFFFF'] }
24 @graph.font = File.expand_path('/usr/X11R6/lib/X11/fonts/TTF/Vera.ttf',
27 if options[:legend_font_size]
28 @graph.legend_font_size = options[:legend_font_size]
31 if options[:title_font_size]
32 @graph.title_font_size = options[:title_font_size]
35 #marker count doesn't include minimum value line, default is 4
36 @graph.marker_count = options[:marker_count] if options[:marker_count]
38 @graph.marker_font_size = options[:marker_font_size] if options[:marker_font_size]
40 @graph.marker_color = options[:marker_color] if options[:marker_color]
42 # fill in the data with the optional data name
43 #Check to see if multiple datasets, if so, fill them all!
44 #Sort by biggest first piece of data.
45 if options[:data].is_a?(Hash)
46 options[:data].sort {|a,b| b[1][0] <=> a[1][0]}.each do |dataset|
47 @graph.data(dataset[0], dataset[1])
49 #if each dataset nameless, will have only multiple arrays
50 elsif options[:data].size > 1 && options[:data].all? {|i| i.is_a?(Array)}
51 options[:data].each do |array|
52 @graph.data( options.fetch(:data_name, "Data"), array)
54 else #one dimensional array, just pass it in
55 @graph.data( options.fetch(:data_name, "Data"), options[:data] )
56 @graph.hide_legend = true
59 # set the labels or create an empty hash
60 @graph.labels = options[:interval_labels] \
61 if options.has_key?(:interval_labels) and \
62 options[:interval_labels].class == Hash
63 @graph.x_axis_label = options[:x_axis_label] \
64 if options.has_key?(:x_axis_label)
65 @graph.y_axis_label = options[:y_axis_label] \
66 if options.has_key?(:y_axis_label)
67 @graph.title = options[:title] if options.has_key?(:title)
69 @graph.minimum_value = 0.0
74 return([@graph.to_blob, {:disposition => 'inline', :type => 'image/png'}])
79 # produce a graph of votes per day during an election
81 @election = Election.find(params[:id])
82 data, labels = get_votes_per_day_data(@election)
84 graph = GruffGraff.new( :graph_type => Gruff::Line,
85 :data_name => @election.name,
87 :interval_labels => labels,
88 :title => "Voters Per Day",
89 :x_axis_label => "Data",
90 :y_axis_label =>"Number of Votes")
91 send_data(*graph.output)
94 #will place votes in a fixed number of intervals, and shows votes over time
95 def votes_per_interval
96 @election = Election.find(params[:id])
97 data, labels, scale = get_votes_per_interval_data(@election)
101 graph = GruffGraff.new( :graph_type => Gruff::Line,
102 :data_name => @election.name,
104 :interval_labels => labels,
105 :title => "Voters Over Time",
107 :legend_font_size => 40,
108 :title_font_size => 50,
110 :marker_font_size => 30,
111 :marker_color => '#999999',
112 :x_axis_label => scale,
113 :y_axis_label => "Number of Votes")
114 send_data(*graph.output)
118 @election = Election.find(params[:id])
119 @election.results unless @election.borda_result
120 data, labels = get_borda_points(@election.borda_result)
123 size = "580x300" if @election.candidates.size >= 5
125 if @election.candidates.size >= 5
126 marker_font_size = 17
128 marker_font_size = 20
131 graph = GruffGraff.new( :graph_type => Gruff::Bar,
132 :data_name => @election.name,
134 :interval_labels => labels,
136 :title => "Points Per Candidate",
137 :marker_color => '#999999',
138 :marker_font_size => marker_font_size,
139 :y_axis_label => "Points",
140 :x_axis_label => "Candidates")
141 send_data(*graph.output)
143 #Acording to Tufte, small, concomparitive, highly labeled data sets usually
144 #belong in tables. The following is a bar graph...but would it be better
146 def choices_positions
147 @election = Election.find(params[:id])
149 alldata, labels = get_positions_info(@election)
150 @election.results unless @election.condorcet_result || @election.ssd_result
151 ranked_candidates = @election.condorcet_result.ranked_candidates.flatten
154 candidates = @election.candidates.sort.collect {|candidate| candidate.id}
155 candidates.each do |candidate|
156 names[candidate]= (Candidate.find(candidate)).name
159 ranked_candidates.each_with_index \
160 {|candidate, index| legend[names[candidate]] = alldata[index]}
162 graph = GruffGraff.new( :graph_type => Gruff::Bar,
164 :interval_labels => labels,
165 :title => "Times Voted in Each Position",
166 :y_axis_label => "Number of Times Ranked",
167 :x_axis_label => "Rank")
168 send_data(*graph.output)
172 @election = Election.find(params[:id])
173 @election.results unless @election.plurality_result || @election.approval_result
174 votes = @election.votes.size
176 names = @election.names_by_id
178 @election.plurality_result.points.each do |candidate, votes|
179 data[names[candidate]] = votes
182 size = "520x300" if @election.candidates.size >= 8
184 if @election.candidates.size >= 8
185 marker_font_size = 20
186 legend_font_size = 17
188 marker_font_size = 17
189 legend_font_size = 17
192 pie = GruffGraff.new( :graph_type => Gruff::Pie,
193 :title => "Percentage of First Place Votes",
195 :marker_font_size => marker_font_size,
196 :legend_font_size => legend_font_size,
198 send_data(*pie.output)
203 def get_positions_info(election)
206 rank_labels = Hash.new
208 #attach the ranking to the candidate's array to which is belongs
209 #creating a key if necessary
210 election.votes.each do |vote|
211 vote.rankings.each do |ranking|
213 unless buckets.has_key?(ranking.candidate_id)
214 buckets[ranking.candidate_id] = []
216 buckets[ranking.candidate_id] << ranking.rank
221 #count how many times each candidate has been ranked at a certain level
222 buckets.each_pair do |id, array|
223 (1..election.candidates.size).each do |i|
224 buckets2[id] = [] unless buckets2.has_key?(id)
225 buckets2[id] << (array.find_all {|rank| rank == i}).size
229 #sort by amount of 1st place votes
230 sorted_data = buckets2.values.sort {|a,b| b[0] <=> a[0]}
232 election.votes.each do |vote|
233 vote.rankings.size.times do |i|
234 rank_labels[i] = (i+1).to_s
238 return sorted_data, rank_labels
241 # generate the data and labels for each graph
242 def get_votes_per_day_data(election)
243 voter_days = Array.new
244 unique_days = Array.new
245 total_per_day = Array.new
246 election_days = Hash.new
248 #turn election startdate into date object, and create the range of election
249 startdate = Date.parse(election.startdate.to_s)
250 election_range = startdate..Date.today
252 # create a hash with all the dates of the election in String format
253 # referenced by their order in the election
254 election_range.each_with_index do |day, index|
255 election_days[index] = day.to_s
258 # Now I need to create an array with all the times votes were made
259 election.votes.each do |vote|
260 next unless vote.time
261 voter_days << Date.parse(vote.time.to_s)
265 # Now I need to count how many times each each date appears in voter_days,
266 # and put that number into a votes_per_day array, the 'data' for the graph
267 #Create an array of unique days from voter_days
268 voter_days.each do |day|
269 unless unique_days.any? {|date| date.eql?(day)}
275 #find all dates where those days = date at current index, put size of returned
276 #array into total_per_day
277 unique_days.each_with_index do |date, index|
278 total_per_day << (voter_days.select {|day| day.eql?(date)}).size
281 # return the data and the labels
282 return total_per_day, election_days
286 def get_votes_per_interval_data(election)
287 labels_hash = Hash.new
289 total_per_interval = Array.new
292 starttime = election.startdate
293 timedelta = Time.now - starttime
295 interval_length = timedelta/numcols
297 # Make a hash, buckets, indexed by time intervals and containing empty arrays
298 # The time object must come first in addition!
299 # i would start at 0, i+1 goes from 1 up till numcols
300 numcols.times {|i| buckets[starttime + ((i+1)*interval_length)] = []}
302 # Put votes into bucket according to the time interval to which they belong,
303 # referenced by their key
304 # Will build a graph over time, as each successive interval will have more
306 election.votes.each do |vote|
307 next unless vote.time
308 buckets.keys.sort.each do |inter|
310 buckets[inter] << vote
315 total_per_interval = buckets.keys.sort.collect {|key| buckets[key].size}
317 # Create the hash for the labels. Each graph has ten columns, and three
319 if timedelta < 2.hours #under two hours use minutes for labels
320 labels_hash[0] = "Start"
321 labels_hash[(numcols/2)-1] = fmt_decimal((timedelta/120)) #halfway
322 labels_hash[numcols-1] = fmt_decimal((timedelta/60))
323 interval_type = "Minutes After Start"
324 elsif timedelta < 2.days #more than 2 hours means use hours for labels
325 labels_hash[0] = "Start"
326 labels_hash[(numcols/2)-1] = fmt_decimal((timedelta/7200))
327 labels_hash[numcols-1] = fmt_decimal((timedelta/3600))
328 interval_type = "Hours After Start (Up to 48)"
329 else #more than 2 days means use dates for labels
330 labels_hash[0] = (Date.parse(starttime.to_s)).to_s
331 labels_hash[(numcols/2)-1] = (Date.parse((starttime + (timedelta/2)).to_s)).to_s
332 labels_hash[numcols-1] = (Date.today).to_s
333 interval_type = "The Date"
336 # Make sure to return an array for data and hash for labels
337 return total_per_interval, labels_hash, interval_type
340 def fmt_decimal(number)
341 sprintf( "%0.1f", number)
344 def get_borda_points(result)
348 #Populate points with an sorted array from election.votes hash
349 #biggest to smallest will go from left to right
350 points = result.points.sort do |a, b|
352 end.collect {|i| i[1]}
355 result.ranked_candidates.each_with_index do |candidate, index|
356 labels[index] = Candidate.find(candidate).name
359 return points, labels
362 #most vote result objects require an array of vote arrays, which this will make
363 def make_preference_tally(election)
364 preference_tally = Array.new
365 @election.voters.each do |voter|
366 next unless voter.voted?
367 preference_tally << voter.vote.rankings.sort.collect \
368 { |ranking| ranking.candidate.id }
370 return preference_tally