From 5d18bc2820500690a584b59225d4513160a13c96 Mon Sep 17 00:00:00 2001
From: James Fiedler <jrfiedler@gmail.com>
Date: Mon, 16 Dec 2019 19:57:17 -0600
Subject: [PATCH] replaced leftover util.entropy

---
 src/classification/tree.jl    |  2 +-
 test/classification/digits.jl | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/classification/tree.jl b/src/classification/tree.jl
index dfa61d9d..b581b72c 100644
--- a/src/classification/tree.jl
+++ b/src/classification/tree.jl
@@ -192,7 +192,7 @@ module treeclassifier
 
         # no splits honor min_samples_leaf
         @inbounds if (unsplittable
-            || (best_purity / nt + util.entropy(nc, nt) < min_purity_increase))
+            || (best_purity / nt + purity_function(nc, nt) < min_purity_increase))
             node.is_leaf = true
             return
         else
diff --git a/test/classification/digits.jl b/test/classification/digits.jl
index f9f267e8..f3917ca2 100644
--- a/test/classification/digits.jl
+++ b/test/classification/digits.jl
@@ -39,6 +39,21 @@ t = DecisionTree.build_tree(
         min_purity_increase)
 @test length(t) == 54
 
+# test that all purity decisions are based on passed-in purity function;
+# if so, this should be same as previous test
+entropy1000(ns, n) = DecisionTree.util.entropy(ns, n) * 1000
+min_samples_leaf    = 3
+min_samples_split   = 5
+min_purity_increase = 0.05 * 1000
+t = DecisionTree.build_tree(
+        Y, X,
+        n_subfeatures, max_depth,
+        min_samples_leaf,
+        min_samples_split,
+        min_purity_increase,
+        loss = entropy1000)
+@test length(t) == 54
+
 n_subfeatures       = 3
 n_trees             = 10
 partial_sampling    = 0.7