third party library: apache-commons-math
Change-Id: I52a325624a7f0dd652b362a9840626d6d9f3c42b
diff --git a/src/main/java/org/apache/commons/math/ode/SecondOrderIntegrator.java b/src/main/java/org/apache/commons/math/ode/SecondOrderIntegrator.java
new file mode 100644
index 0000000..f744e85
--- /dev/null
+++ b/src/main/java/org/apache/commons/math/ode/SecondOrderIntegrator.java
@@ -0,0 +1,60 @@
+/*
+ * 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.math.ode;
+
+import org.apache.commons.math.ode.DerivativeException;
+
+
+/** This interface represents a second order integrator for
+ * differential equations.
+ *
+ * <p>The classes which are devoted to solve second order differential
+ * equations should implement this interface. The problems which can
+ * be handled should implement the {@link
+ * SecondOrderDifferentialEquations} interface.</p>
+ *
+ * @see SecondOrderDifferentialEquations
+ * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 févr. 2011) $
+ * @since 1.2
+ */
+
+public interface SecondOrderIntegrator extends ODEIntegrator {
+
+ /** Integrate the differential equations up to the given time
+ * @param equations differential equations to integrate
+ * @param t0 initial time
+ * @param y0 initial value of the state vector at t0
+ * @param yDot0 initial value of the first derivative of the state
+ * vector at t0
+ * @param t target time for the integration
+ * (can be set to a value smaller thant <code>t0</code> for backward integration)
+ * @param y placeholder where to put the state vector at each
+ * successful step (and hence at the end of integration), can be the
+ * same object as y0
+ * @param yDot placeholder where to put the first derivative of
+ * the state vector at time t, can be the same object as yDot0
+ * @throws IntegratorException if the integrator cannot perform integration
+ * @throws DerivativeException this exception is propagated to the caller if the
+ * underlying user function triggers one
+ */
+ void integrate(SecondOrderDifferentialEquations equations,
+ double t0, double[] y0, double[] yDot0,
+ double t, double[] y, double[] yDot)
+ throws DerivativeException, IntegratorException;
+
+}