Added tests for 3/8 integrator.

src/test/java/org/apache/commons/math4/ode/nonstiff/ThreeEighthesFieldIntegratorTest.java

@@ -0,0 +1,99 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math4.ode.nonstiff;
+
+
+import org.apache.commons.math4.Field;
+import org.apache.commons.math4.RealFieldElement;
+import org.apache.commons.math4.util.Decimal64Field;
+import org.junit.Test;
+
+public class ThreeEighthesFieldIntegratorTest extends AbstractRungeKuttaFieldIntegratorTest {
+
+    protected <T extends RealFieldElement<T>> RungeKuttaFieldIntegrator<T>
+    createIntegrator(Field<T> field, T step) {
+        return new ThreeEighthesFieldIntegrator<T>(field, step);
+    }
+
+    @Test
+    public void testNonFieldIntegratorConsistency() {
+        doTestNonFieldIntegratorConsistency(Decimal64Field.getInstance());
+    }
+
+    @Test
+    public void testMissedEndEvent() {
+        doTestMissedEndEvent(Decimal64Field.getInstance(), 1.0e-15, 6.0e-5);
+    }
+
+    @Test
+    public void testSanityChecks() {
+        doTestSanityChecks(Decimal64Field.getInstance());
+    }
+
+    @Test
+    public void testDecreasingSteps() {
+        doTestDecreasingSteps(Decimal64Field.getInstance(), 1.0, 1.0, 1.0e-10);
+    }
+
+    @Test
+    public void testSmallStep() {
+        doTestSmallStep(Decimal64Field.getInstance(), 2.0e-13, 4.0e-12, 1.0e-12, "3/8");
+    }
+
+    @Test
+    public void testBigStep() {
+        doTestBigStep(Decimal64Field.getInstance(), 0.0004, 0.005, 1.0e-12, "3/8");
+
+    }
+
+    @Test
+    public void testBackward() {
+        doTestBackward(Decimal64Field.getInstance(), 5.0e-10, 7.0e-10, 1.0e-12, "3/8");
+    }
+
+    @Test
+    public void testKepler() {
+        doTestKepler(Decimal64Field.getInstance(), 0.0348, 1.0e-4);
+    }
+
+    @Test
+    public void testStepSize() {
+        doTestStepSize(Decimal64Field.getInstance(), 1.0e-12);
+    }
+
+    @Test
+    public void testSingleStep() {
+        doTestSingleStep(Decimal64Field.getInstance(), 0.21);
+    }
+
+    @Test
+    public void testTooLargeFirstStep() {
+        doTestTooLargeFirstStep(Decimal64Field.getInstance());
+    }
+
+    @Test
+    public void testUnstableDerivative() {
+        doTestUnstableDerivative(Decimal64Field.getInstance(), 1.0e-12);
+    }
+
+    @Test
+    public void testDerivativesConsistency() {
+        doTestDerivativesConsistency(Decimal64Field.getInstance(), 1.0e-10);
+    }
+
+}