Remove duplicate function (unit tests).
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/TestFunction.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/TestFunction.java
index 2dd7048..44ebc4f 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/TestFunction.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/TestFunction.java
@@ -104,19 +104,6 @@
                 return f;
             };
         }),
-    ROSEN(dim -> {
-            final int last = dim - 1;
-            return x -> {
-                double f = 0;
-                for (int i = 0; i < last; i++) {
-                    final double xi = x[i];
-                    final double a = xi * xi - x[i + 1];
-                    final double b = xi - 1;
-                    f += 1e2 * a * a + b * b;
-                }
-                return f;
-            };
-        }),
     ACKLEY(dim -> {
             final double A = 20;
             final double B = 0.2;
@@ -176,7 +163,7 @@
                     final double xiP1 = x[i + 1];
                     final double a = xiP1 - xi * xi;
                     final double b = xi - 1;
-                    f += 100 * a * a + b * b;
+                    f += 1e2 * a * a + b * b;
                 }
                 return f;
             };
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/BOBYQAOptimizerTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/BOBYQAOptimizerTest.java
index 020c67d..bd6cd3a 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/BOBYQAOptimizerTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/BOBYQAOptimizerTest.java
@@ -42,7 +42,7 @@
     public void testInitOutOfBounds() {
         double[] startPoint = OptimTestUtils.point(DIM, 3);
         double[][] boundaries = boundaries(DIM, -1, 2);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, boundaries,
                 GoalType.MINIMIZE,
                 1e-13, 1e-6, 2000, null);
     }
@@ -51,7 +51,7 @@
     public void testBoundariesDimensionMismatch() {
         double[] startPoint = OptimTestUtils.point(DIM, 0.5);
         double[][] boundaries = boundaries(DIM + 1, -1, 2);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, boundaries,
                GoalType.MINIMIZE,
                1e-13, 1e-6, 2000, null);
     }
@@ -59,7 +59,7 @@
     @Test(expected=NumberIsTooSmallException.class)
     public void testProblemDimensionTooSmall() {
         double[] startPoint = OptimTestUtils.point(1, 0.5);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, null,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, null,
                GoalType.MINIMIZE,
                1e-13, 1e-6, 2000, null);
     }
@@ -69,7 +69,7 @@
         final int lowMaxEval = 2;
         double[] startPoint = OptimTestUtils.point(DIM, 0.1);
         double[][] boundaries = null;
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, boundaries,
                GoalType.MINIMIZE,
                1e-13, 1e-6, lowMaxEval, null);
      }
@@ -79,7 +79,7 @@
         double[] startPoint = OptimTestUtils.point(DIM,0.1);
         double[][] boundaries = null;
         PointValuePair expected = new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, boundaries,
                 GoalType.MINIMIZE,
                 1e-13, 1e-6, 2000, expected);
      }
@@ -230,7 +230,7 @@
         double[][] boundaries = boundaries(DIM,-1,2);
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, boundaries,
                 GoalType.MINIMIZE,
                 1e-13, 1e-6, 2000, expected);
     }
@@ -252,7 +252,7 @@
         final int maxAdditionalPoints = 47;
 
         for (int num = 1; num <= maxAdditionalPoints; num++) {
-            doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, boundaries,
+            doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, boundaries,
                    GoalType.MINIMIZE,
                    1e-12, 1e-6, 2000,
                    num,
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/CMAESOptimizerTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/CMAESOptimizerTest.java
index 6b307b0..bf9bdb4 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/CMAESOptimizerTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/CMAESOptimizerTest.java
@@ -53,7 +53,7 @@
         double[][] boundaries = boundaries(DIM,-1,2);
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -64,7 +64,7 @@
         double[][] boundaries = boundaries(DIM,-1,2);
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -76,7 +76,7 @@
         double[][] boundaries = boundaries(DIM+1,-1,2);
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -88,7 +88,7 @@
         double[][] boundaries = null;
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -100,7 +100,7 @@
         double[][] boundaries = boundaries(DIM,-0.5,0.5);
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -112,7 +112,7 @@
         double[][] boundaries = null;
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -125,10 +125,10 @@
         double[][] boundaries = null;
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, false, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -365,10 +365,10 @@
         double[][] boundaries = boundaries(DIM, -1, 2);
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, 2*LAMBDA, true, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, 2*LAMBDA, false, 0, 1e-13,
                 1e-13, 1e-6, 100000, expected);
     }
@@ -380,7 +380,7 @@
         double[][] boundaries = null;
         PointValuePair expected =
             new PointValuePair(OptimTestUtils.point(DIM,1.0),0.0);
-        doTest(TestFunction.ROSEN.withDimension(DIM), startPoint, insigma, boundaries,
+        doTest(TestFunction.ROSENBROCK.withDimension(DIM), startPoint, insigma, boundaries,
                 GoalType.MINIMIZE, LAMBDA, false, 1, 1e-13,
                 1e-10, 1e-4, 1000000, expected);
      }
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerMultiDirectionalTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerMultiDirectionalTest.java
index a652cfb..a381212 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerMultiDirectionalTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerMultiDirectionalTest.java
@@ -142,16 +142,6 @@
                2e-4);
     }
 
-    @Test
-    public void testRosen() {
-        doTest(TestFunction.ROSEN.withDimension(DIM),
-               OptimTestUtils.point(DIM, 0.1),
-               GoalType.MINIMIZE,
-               186915,
-               new PointValuePair(OptimTestUtils.point(DIM, 1.0), 0.0),
-               1e-4);
-    }
-
     @Ignore("See MATH-1552")@Test
     public void testEllipse() {
         doTest(TestFunction.ELLI.withDimension(DIM),
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerNelderMeadTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerNelderMeadTest.java
index e2ed741..9b191b4 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerNelderMeadTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/optim/nonlinear/scalar/noderiv/SimplexOptimizerNelderMeadTest.java
@@ -226,16 +226,6 @@
                2e-4);
     }
 
-    @Test
-    public void testRosen() {
-        doTest(TestFunction.ROSEN.withDimension(DIM),
-               OptimTestUtils.point(DIM, 0.1),
-               GoalType.MINIMIZE,
-               9078,
-               new PointValuePair(OptimTestUtils.point(DIM, 1.0), 0.0),
-               1e-6);
-    }
-
     @Ignore("See MATH-1552")@Test
     public void testEllipse() {
         doTest(TestFunction.ELLI.withDimension(DIM),