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From l..@apache.org
Subject [math] Top level integrator interface.
Date Wed, 11 Nov 2015 20:35:15 GMT
Repository: commons-math
Updated Branches:
  refs/heads/field-ode 89e621968 -> 62ef50bc7


Top level integrator interface.

We have merged together what was initially in an integrator interface
and in an AbstractIntegrator class. The separation was only due to
backward compatibility issues which prevented to push some functions up
in the interface. A consequence was that users needed to use the
abstract class in their declaration as soon as they needed the
additional features ... which was most of the cases. We try to fix this
here. When 4.0 will be out, the same merging will be done in the
double[] implementation of ode.

JIRA: MATH-1288

Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo
Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/62ef50bc
Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/62ef50bc
Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/62ef50bc

Branch: refs/heads/field-ode
Commit: 62ef50bc7599afb2929a233ef22afa00754b9bd2
Parents: 89e6219
Author: Luc Maisonobe <luc@apache.org>
Authored: Wed Nov 11 21:35:01 2015 +0100
Committer: Luc Maisonobe <luc@apache.org>
Committed: Wed Nov 11 21:35:01 2015 +0100

----------------------------------------------------------------------
 .../math3/ode/FieldFirstOrderIntegrator.java    | 168 +++++++++++++++++++
 1 file changed, 168 insertions(+)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/commons-math/blob/62ef50bc/src/main/java/org/apache/commons/math3/ode/FieldFirstOrderIntegrator.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/commons/math3/ode/FieldFirstOrderIntegrator.java b/src/main/java/org/apache/commons/math3/ode/FieldFirstOrderIntegrator.java
new file mode 100644
index 0000000..973b59c
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/ode/FieldFirstOrderIntegrator.java
@@ -0,0 +1,168 @@
+/*
+ * 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.math3.ode;
+
+import java.util.Collection;
+
+import org.apache.commons.math3.RealFieldElement;
+import org.apache.commons.math3.exception.DimensionMismatchException;
+import org.apache.commons.math3.exception.MaxCountExceededException;
+import org.apache.commons.math3.exception.NoBracketingException;
+import org.apache.commons.math3.exception.NumberIsTooSmallException;
+import org.apache.commons.math3.ode.events.FieldEventHandler;
+import org.apache.commons.math3.ode.sampling.FieldStepHandler;
+
+/** This interface represents a first order integrator for
+ * differential equations.
+
+ * <p>The classes which are devoted to solve first order differential
+ * equations should implement this interface. The problems which can
+ * be handled should implement the {@link
+ * FirstOrderDifferentialEquations} interface.</p>
+ *
+ * @see FieldFirstOrderDifferentialEquations
+ * @param <T> the type of the field elements
+ * @since 3.6
+ */
+
+public interface FieldFirstOrderIntegrator<T extends RealFieldElement<T>> {
+
+    /** Get the name of the method.
+     * @return name of the method
+     */
+    String getName();
+
+    /** Add a step handler to this integrator.
+     * <p>The handler will be called by the integrator for each accepted
+     * step.</p>
+     * @param handler handler for the accepted steps
+     * @see #getStepHandlers()
+     * @see #clearStepHandlers()
+     */
+    void addStepHandler(FieldStepHandler<T> handler);
+
+    /** Get all the step handlers that have been added to the integrator.
+     * @return an unmodifiable collection of the added events handlers
+     * @see #addStepHandler(FieldStepHandler)
+     * @see #clearStepHandlers()
+     */
+    Collection<FieldStepHandler<T>> getStepHandlers();
+
+    /** Remove all the step handlers that have been added to the integrator.
+     * @see #addStepHandler(StepHandler)
+     * @see #getStepHandlers()
+     */
+    void clearStepHandlers();
+
+    /** Add an event handler to the integrator.
+     * @param handler event handler
+     * @param maxCheckInterval maximal time interval between switching
+     * function checks (this interval prevents missing sign changes in
+     * case the integration steps becomes very large)
+     * @param convergence convergence threshold in the event time search
+     * @param maxIterationCount upper limit of the iteration count in
+     * the event time search
+     * events.
+     * @see #getEventHandlers()
+     * @see #clearEventHandlers()
+     */
+    void addEventHandler(FieldEventHandler<T>  handler, double maxCheckInterval,
+                         double convergence, int maxIterationCount);
+
+    /** Get all the event handlers that have been added to the integrator.
+     * @return an unmodifiable collection of the added events handlers
+     * @see #addEventHandler(EventHandler, double, double, int)
+     * @see #clearEventHandlers()
+     */
+    Collection<FieldEventHandler<T> > getEventHandlers();
+
+    /** Remove all the event handlers that have been added to the integrator.
+     * @see #addEventHandler(EventHandler, double, double, int)
+     * @see #getEventHandlers()
+     */
+    void clearEventHandlers();
+
+    /** Get the current value of the step start time t<sub>i</sub>.
+     * <p>This method can be called during integration (typically by
+     * the object implementing the {@link FirstOrderDifferentialEquations
+     * differential equations} problem) if the value of the current step that
+     * is attempted is needed.</p>
+     * <p>The result is undefined if the method is called outside of
+     * calls to <code>integrate</code>.</p>
+     * @return current value of the step start time t<sub>i</sub>
+     */
+    T getCurrentStepStart();
+
+    /** Get the current signed value of the integration stepsize.
+     * <p>This method can be called during integration (typically by
+     * the object implementing the {@link FirstOrderDifferentialEquations
+     * differential equations} problem) if the signed value of the current stepsize
+     * that is tried is needed.</p>
+     * <p>The result is undefined if the method is called outside of
+     * calls to <code>integrate</code>.</p>
+     * @return current signed value of the stepsize
+     */
+    T getCurrentSignedStepsize();
+
+    /** Set the maximal number of differential equations function evaluations.
+     * <p>The purpose of this method is to avoid infinite loops which can occur
+     * for example when stringent error constraints are set or when lots of
+     * discrete events are triggered, thus leading to many rejected steps.</p>
+     * @param maxEvaluations maximal number of function evaluations (negative
+     * values are silently converted to maximal integer value, thus representing
+     * almost unlimited evaluations)
+     */
+    void setMaxEvaluations(int maxEvaluations);
+
+    /** Get the maximal number of functions evaluations.
+     * @return maximal number of functions evaluations
+     */
+    int getMaxEvaluations();
+
+    /** Get the number of evaluations of the differential equations function.
+     * <p>
+     * The number of evaluations corresponds to the last call to the
+     * <code>integrate</code> method. It is 0 if the method has not been called
yet.
+     * </p>
+     * @return number of evaluations of the differential equations function
+     */
+    int getEvaluations();
+
+    /** Integrate the differential equations up to the given time.
+     * <p>This method solves an Initial Value Problem (IVP).</p>
+     * <p>Since this method stores some internal state variables made
+     * available in its public interface during integration ({@link
+     * #getCurrentSignedStepsize()}), it is <em>not</em> thread-safe.</p>
+     * @param equations differential equations to integrate
+     * @param initialState initial state (time, primary and secondary state vectors)
+     * @param finalTime target time for the integration
+     * (can be set to a value smaller than {@code t0} for backward integration)
+     * @return final state, its time will be the same as {@code finalTime} if
+     * integration reached its target, but may be different if some {@link
+     * org.apache.commons.math3.ode.events.FieldEventHandler} stops it at some point.
+     * @exception DimensionMismatchException if arrays dimension do not match equations settings
+     * @exception NumberIsTooSmallException if integration step is too small
+     * @exception MaxCountExceededException if the number of functions evaluations is exceeded
+     * @exception NoBracketingException if the location of an event cannot be bracketed
+     */
+    FieldODEStateAndDerivative<T> integrate (FieldExpandableODE<T> equations,
+                                             FieldODEState<T>initialState, T finalTime)
+        throws DimensionMismatchException, NumberIsTooSmallException,
+        MaxCountExceededException, NoBracketingException;
+
+}


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