Module: Spark

Defined in:
lib/spark_pr.rb

Class Method Summary collapse

Class Method Details

.discrete(results, options = {}) ⇒ Object 



183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
 
# File 'lib/spark_pr.rb', line 183

def Spark.discrete( results, options = {} )
  options = self.process_options(options)
  o = {
    :height => 14,
    :upper => 0.5,
    :has_min => false,
    :has_max => false
  }.merge(options)
  
  o[:width] ||= results.size*2-1
  
  c = SparkCanvas.new(o[:width], o[:height])
  
  results = Spark.normalize(results, o[:normalize])
  fac = c.height-4
      
  i = -2
  results.each do |r|
    p = c.height - 4 - r*fac
    c.color = r < o[:upper] ? [0x66,0x66,0x66,0xFF] : [0xFF,0x00,0x00,0xFF] 
    c.line(i+=2, p, i, p+3)
  end
      
  c
end

.normalize(arr, type = :linear) ⇒ Object

normalize arr to contain values between 0..1 inclusive



119
120
121
122
123
 
# File 'lib/spark_pr.rb', line 119

def Spark.normalize( arr, type = :linear )
  arr.map!{|v| Math.log(v) } if type == :logarithmic
  adj, fac = arr.min, arr.max-arr.min
  arr.map {|v| (v-adj).quo(fac) rescue 0 }
end

.plot(results, options = {}) ⇒ Object

convenience method



210
211
212
213
214
 
# File 'lib/spark_pr.rb', line 210

def Spark.plot( results, options = {})
  options = self.process_options(options)
  options[:type] ||= 'smooth'
  self.send(options[:type], results, options).to_png
end

.process_options(options) ⇒ Object 



125
126
127
128
129
130
131
132
133
134
135
136
137
138
 
# File 'lib/spark_pr.rb', line 125

def Spark.process_options( options )
  o = options.inject({}) do |o, (key, value)|
    o[key.to_sym] = value ; o
  end
  [:height, :width, :step].each do |k|
    o[k] = o[k].to_i if o.has_key?(k)
  end
  [:has_min, :has_max, :has_last].each do |k|
    o[k] = (o[k] ? true : false) if o.has_key?(k)
  end
  o[:normalize] ||= :linear
  o[:normalize] = o[:normalize].to_sym
  o
end

.smooth(results, options = {}) ⇒ Object 



140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
 
# File 'lib/spark_pr.rb', line 140

def Spark.smooth( results, options = {} )
  options = self.process_options(options)
  o = {
    :step => 2,
    :height => 14,
    :has_min => false,
    :has_max => false
  }.merge(options)
  
  o[:width] ||= (results.size-1)*o[:step] + 5
  
  c = SparkCanvas.new(o[:width], o[:height])
  
  results = Spark.normalize(results, o[:normalize])
  fac = c.height-5
  i = -o[:step]
  coords = results.map do |r| 
    [(i += o[:step])+2, c.height - 3 - r*fac ]
  end
  
  c.color = [0xB0, 0xB0, 0xB0, 0xFF]
  c.polyline coords
  
  if o[:has_min]
    min_pt = coords[results.index(results.min)]
    c.color = [0x80, 0x80, 0x00, 0x70]
    c.rectangle(min_pt[0]-2, min_pt[1]-2, min_pt[0]+2, min_pt[1]+2)
  end
  
  if o[:has_max]
    max_pt = coords[results.index(results.max)]
    c.color = [0x00, 0x80, 0x00, 0x70]
    c.rectangle(max_pt[0]-2, max_pt[1]-2, max_pt[0]+2, max_pt[1]+2)
  end
  
  if o[:has_last]
    c.color = [0xFF, 0x00, 0x00, 0x70]
    c.rectangle(coords.last[0]-2, coords.last[1]-2, coords.last[0]+2, coords.last[1]+2)
  end
  
  c
end