From f01258fff1c9bac02296943cc38cab90a0457823 Mon Sep 17 00:00:00 2001
From: Fabian Becker <halfdan@xnorfz.de>
Date: Mon, 1 Dec 2014 19:22:30 +0100
Subject: [PATCH] Fix Step function and add test for known optimum.

---
 src/eva2/problems/F3Problem.java      |  8 +++++---
 test/eva2/problems/F3ProblemTest.java | 24 ++++++++++++++++++++++++
 test/eva2/tools/SerializerTest.java   |  2 --
 3 files changed, 29 insertions(+), 5 deletions(-)
 create mode 100644 test/eva2/problems/F3ProblemTest.java

diff --git a/src/eva2/problems/F3Problem.java b/src/eva2/problems/F3Problem.java
index 9ebab745..696f01f3 100644
--- a/src/eva2/problems/F3Problem.java
+++ b/src/eva2/problems/F3Problem.java
@@ -28,7 +28,9 @@ public class F3Problem extends AbstractProblemDoubleOffset implements java.io.Se
     }
 
     /**
-     * Ths method allows you to evaluate a double[] to determine the fitness
+     * Evaluates a double vector according to the Step function.
+     *
+     * fitness = sum(floor(x_i + 0.5)^2)
      *
      * @param x The n-dimensional input vector
      * @return The m-dimensional output vector.
@@ -37,9 +39,9 @@ public class F3Problem extends AbstractProblemDoubleOffset implements java.io.Se
     public double[] evaluate(double[] x) {
         x = rotateMaybe(x);
         double[] result = new double[1];
-        result[0] = yOffset + 6 * x.length;
+        result[0] = yOffset;
         for (int i = 0; i < x.length - 1; i++) {
-            result[0] += Math.floor(x[i] - this.xOffset);
+            result[0] += Math.pow(Math.floor(x[i] + 0.5 - this.xOffset), 2);
         }
         return result;
     }
diff --git a/test/eva2/problems/F3ProblemTest.java b/test/eva2/problems/F3ProblemTest.java
new file mode 100644
index 00000000..05b84524
--- /dev/null
+++ b/test/eva2/problems/F3ProblemTest.java
@@ -0,0 +1,24 @@
+package eva2.problems;
+
+import eva2.tools.math.Mathematics;
+import junit.framework.TestCase;
+
+public class F3ProblemTest extends TestCase {
+
+    /**
+     * The Step function has its minimum
+     * at x_{i} = 0
+     *
+     * @throws Exception
+     */
+    public void testEvaluate() throws Exception {
+        F3Problem problem = new F3Problem();
+
+        for (int i = 1; i < 100; i++) {
+            double[] x = Mathematics.zeroes(i);
+            double[] res = problem.evaluate(x);
+            assertEquals(1, res.length);
+            assertEquals(0.0, res[0]);
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/eva2/tools/SerializerTest.java b/test/eva2/tools/SerializerTest.java
index 23bcaa28..9082f127 100644
--- a/test/eva2/tools/SerializerTest.java
+++ b/test/eva2/tools/SerializerTest.java
@@ -68,7 +68,6 @@ public class SerializerTest {
      */
     @Test
     public void testStoreObject() {
-        System.out.println("storeObject");
         OutputStream outStream = null;
         Serializable s = null;
         Serializer.storeObject(outStream, s);
@@ -81,7 +80,6 @@ public class SerializerTest {
      */
     @Test
     public void testLoadObject_InputStream() {
-        System.out.println("loadObject");
         InputStream inputStream = null;
         Object expResult = null;
         Object result = Serializer.loadObject(inputStream);