histogram.rb in ruby-metrics-0.9.0

- old
+ new

@@ -1,9 +1,12 @@
+require 'ruby-metrics/statistics/uniform_sample'
+require 'ruby-metrics/statistics/exponential_sample'
+
 module Metrics
   module Instruments
-    class Histogram < Base
-      
+    class Histogram
+
       def initialize(type = :uniform)
         @count = 0
         case type
         when :uniform
           @sample = Metrics::Statistics::UniformSample.new
@@ -14,43 +17,43 @@
         @max = nil
         @sum = 0
         @variance_s = 0
         @variance_m = -1
       end
-      
+
       def update(value)
       	@count += 1
       	@sum += value
       	@sample.update(value)
       	update_max(value)
       	update_min(value)
         update_variance(value);
       end
-      
-      def clear 
+
+      def clear
         @sample.clear
         @min = nil
         @max = nil
         @sum = 0
         @count = 0
         @variance_m = -1
         @variance_s = 0
       end
-      
+
       def quantiles(percentiles)
         # Calculated using the same logic as R and Ecxel use
         # as outlined by the NIST here: http://www.itl.nist.gov/div898/handbook/prc/section2/prc252.htm
         count = @count
         scores = {}
         values = @sample.values[0..count-1]
-      
+
         percentiles.each do |pct|
           scores[pct] = 0.0
         end
-        
+
         if count > 0
-          values.sort!          
+          values.sort!
           percentiles.each do |pct|
             idx = pct * (values.length - 1) + 1.0
             if idx <= 1
               scores[pct] = values[0]
             elsif idx >= values.length
@@ -60,122 +63,120 @@
               upper = values[idx.to_i]
               scores[pct] = lower + (idx - idx.floor) * (upper - lower)
             end
           end
         end
-        
+
         return scores
       end
-      
+
       def update_min(value)
         if (@min == nil || value < @min)
-          @min = value 
+          @min = value
         end
       end
-      
+
       def update_max(value)
         if (@max == nil || value > @max)
-          @max = value 
-        end        
+          @max = value
+        end
       end
-      
+
       def update_variance(value)
         count = @count
         old_m = @variance_m
         new_m = @variance_m + ((value - old_m) / count)
         new_s = @variance_s + ((value - old_m) * (value - new_m))
-        
+
         @variance_m = new_m
         @variance_s = new_s
       end
-      
+
       def variance
         count = @count
-        variance_s = @variance_s 
-        
-        if count <= 1 
+        variance_s = @variance_s
+
+        if count <= 1
           return 0.0
         else
           return variance_s.to_f / (count - 1).to_i
         end
       end
-      
+
       def count
         count = @count
         return count
       end
-      
-      
+
+
       def max
         max = @max
         if max != nil
           return max
         else
           return 0.0
         end
       end
-      
+
       def min
         min = @min
         if min != nil
           return min
         else
           return 0.0
         end
       end
-      
+
       def mean
         count = @count
         sum = @sum
-        
+
         if count > 0
           return sum / count
         else
           return 0.0
         end
       end
-      
-      def std_dev 
+
+      def std_dev
         count = @count
         variance = self.variance()
-        
+
         if count > 0
           return Math.sqrt(variance)
-        else 
+        else
           return 0.0
         end
       end
-      
+
       def values
         @sample.values
       end
-      
-      def to_json(*_)
+
+      def as_json(*_)
         {
-          :min => self.min, 
+          :min => self.min,
           :max => self.max,
-          :mean => self.mean, 
-          :variance => self.variance, 
+          :mean => self.mean,
+          :variance => self.variance,
           :percentiles => self.quantiles([0.25, 0.50, 0.75, 0.95, 0.97, 0.98, 0.99])
-        }.to_json
+        }
       end
-    
+
+      def to_json(*_)
+        as_json.to_json
+      end
     end
-  
+
     class ExponentialHistogram < Histogram
       def initialize
         super(:exponential)
       end
     end
 
-    register_instrument(:exponential_histogram, ExponentialHistogram)
-
     class UniformHistogram < Histogram
       def initialize
         super(:uniform)
       end
     end
-
-    register_instrument(:uniform_histogram, UniformHistogram)
   end
-  
 end