confidence = similarity to nearest neighbor

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/regression.rb b/lib/regression.rb
index 2580a1e..9062a9e 100644
--- a/lib/regression.rb
+++ b/lib/regression.rb
@@ -22,15 +22,18 @@ module OpenTox
       def self.weighted_average compound, params
         weighted_sum = 0.0
         sim_sum = 0.0
+        confidence = 0.0
         neighbors = params[:neighbors]
         neighbors.each do |row|
           n,sim,acts = row
+          confidence = sim if sim > confidence # distance to nearest neighbor
+          # TODO add LOO errors
           acts.each do |act|
             weighted_sum += sim*Math.log10(act)
             sim_sum += sim
           end
         end
-        confidence = sim_sum*neighbors.size.to_f/params[:training_dataset_size]
+        #confidence = sim_sum*neighbors.size.to_f/params[:training_dataset_size]
         sim_sum == 0 ? prediction = nil : prediction = 10**(weighted_sum/sim_sum)
         {:value => prediction,:confidence => confidence}
       end