added support for continuous and discrete attributes in the same dataset

spec/id3_spec.rb

@@ -0,0 +1,64 @@
+require 'spec_helper'
+
+describe describe DecisionTree::ID3Tree do
+
+  describe "discrete attributes" do
+    Given(:labels) { ["hungry", "color"] }
+    Given(:data) do
+      [
+        ["yes", "red", "angry"],
+        ["no", "blue", "not angry"],
+        ["yes", "blue", "not angry"],
+        ["no", "red", "not angry"]
+      ]
+    end
+    Given(:tree) { DecisionTree::ID3Tree.new(labels, data, "not angry", :discrete) }
+    When { tree.train }
+    Then { tree.predict(["yes", "red"]).should == "angry" }
+    Then { tree.predict(["no", "red"]).should == "not angry" }
+  end
+
+  describe "discrete attributes" do
+    Given(:labels) { ["hunger", "happiness"] }
+    Given(:data) do
+      [
+        [8, 7, "angry"],
+        [6, 7, "angry"],
+        [7, 9, "angry"],
+        [7, 1, "not angry"],
+        [2, 9, "not angry"],
+        [3, 2, "not angry"],
+        [2, 3, "not angry"],
+        [1, 4, "not angry"]
+      ]
+    end
+    Given(:tree) { DecisionTree::ID3Tree.new(labels, data, "not angry", :continuous) }
+    When { tree.train }
+    Then { tree.graph("continuous") }
+    Then { tree.predict([7, 7]).should == "angry" }
+    Then { tree.predict([2, 3]).should == "not angry" }
+  end
+
+  describe "a mixture" do
+    Given(:labels) { ["hunger", "color"] }
+    Given(:data) do
+      [
+        [8, "red", "angry"],
+        [6, "red", "angry"],
+        [7, "red", "angry"],
+        [7, "blue", "not angry"],
+        [2, "red", "not angry"],
+        [3, "blue", "not angry"],
+        [2, "blue", "not angry"],
+        [1, "red", "not angry"]
+      ]
+    end
+    Given(:tree) { DecisionTree::ID3Tree.new(labels, data, "not angry", color: :discrete, hunger: :continuous) }
+    When { tree.train }
+    Then { tree.graph("continuous") }
+    Then { tree.predict([7, "red"]).should == "angry" }
+    Then { tree.predict([2, "blue"]).should == "not angry" }
+  end
+
+
+end

spec/spec_helper.rb

@@ -0,0 +1,3 @@
+require 'rspec/given'
+require 'decisiontree'
+require 'pry'