updating to support passing model paramters and returning accuracy from the function along with prediction

src/pg/sql/05_segmentation.sql

@@ -2,11 +2,18 @@ CREATE OR REPLACE FUNCTION
   CDB_CreateAndPredictSegment (
       query TEXT,
       variable_name TEXT,
-      target_table TEXT
+      target_table TEXT,
+      n_estimators INTEGER DEFAULT 1200,
+      max_depth INTEGER DEFAULT 3,
+      subsample DOUBLE PRECISION DEFAULT 0.5,
+      learning_rate DOUBLE PRECISION DEFAULT 0.01,
+      min_samples_leaf INTEGER DEFAULT 1
+
   )
-RETURNS TABLE (cartodb_id text, prediction Numeric )
+RETURNS TABLE (cartodb_id text, prediction Numeric,accuracy Numeric )
 AS $$
   from crankshaft.segmentation import create_and_predict_segment
-  # TODO: use named parameters or a dictionary
-  return create_and_predict_segment(query,variable_name,target_table)
+  model_params = {'n_estimators': n_estimators, 'max_depth':max_depth, 'subsample' : subsample, 'learning_rate': learning_rate, 'min_samples_leaf' : min_samples_leaf} 
+  return create_and_predict_segment(query,variable_name,target_table, model_params)
 $$ LANGUAGE plpythonu;
+