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From l..@apache.org
Subject [29/50] [abbrv] [math] Notify availability of field-based ode.
Date Wed, 06 Jan 2016 13:50:45 GMT
Notify availability of field-based ode.


Project: http://git-wip-us.apache.org/repos/asf/commons-math/repo
Commit: http://git-wip-us.apache.org/repos/asf/commons-math/commit/c246b37d
Tree: http://git-wip-us.apache.org/repos/asf/commons-math/tree/c246b37d
Diff: http://git-wip-us.apache.org/repos/asf/commons-math/diff/c246b37d

Branch: refs/heads/master
Commit: c246b37dbe38b16ded570b2280af8f21fb95618a
Parents: 11df45b
Author: Luc Maisonobe <luc@apache.org>
Authored: Wed Jan 6 13:20:25 2016 +0100
Committer: Luc Maisonobe <luc@apache.org>
Committed: Wed Jan 6 13:20:25 2016 +0100

----------------------------------------------------------------------
 src/site/xdoc/userguide/ode.xml | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/commons-math/blob/c246b37d/src/site/xdoc/userguide/ode.xml
----------------------------------------------------------------------
diff --git a/src/site/xdoc/userguide/ode.xml b/src/site/xdoc/userguide/ode.xml
index b2fe395..3dc48bc 100644
--- a/src/site/xdoc/userguide/ode.xml
+++ b/src/site/xdoc/userguide/ode.xml
@@ -69,11 +69,27 @@
           derivatives being handled be secondary ODE (see below for an example).
         </p>
         <p>
+         Two parallel APIs are available. The first is devoted to solve ode for which the
integration free
+         variable t and the state y(t) are primitive double and primitive double array respectively.
Starting
+         with version 3.6, a second API is devoted to solve ode for which the integration
free
+         variable t and the state y(t) are <code>RealFieldElement</code> and
<code>RealFieldElement</code>
+         array respectively. This allow for example users to integrate ode where the computation
values
+         are for example <code>DerivativeStructure</code> elements, hence automatically
computing
+         partial derivatives with respect to some equations parameters without a need to
set up the
+         variational equations. Another example is to use <code>Dfp</code> elements
in order to solve
+         ode with extended precision. As of 3.6, the API are slightly different, mainly in
the way they
+         handle arrays. Both API will become more similar in 4.0 and future versions as the
older
+         primitive double API will be modified to match the newer field API. This cannot
be done in
+         3.6 for compatibility reasons.
+        </p>
+        <p>
           The user should describe his problem in his own classes which should implement
the
           <a href="../apidocs/org/apache/commons/math4/ode/FirstOrderDifferentialEquations.html">FirstOrderDifferentialEquations</a>
-          interface. Then he should pass it to the integrator he prefers among all the classes
that implement
+          interface (or  <a href="../apidocs/org/apache/commons/math4/ode/FieldFirstOrderDifferentialEquations.html">FieldFirstOrderDifferentialEquations</a>
+          interface). Then he should pass it to the integrator he prefers among all the classes
that implement
           the <a href="../apidocs/org/apache/commons/math4/ode/FirstOrderIntegrator.html">FirstOrderIntegrator</a>
-          interface. The following example shows how to implement the simple two-dimensional
problem:
+          interface (or the <a href="../apidocs/org/apache/commons/math4/ode/FieldFirstOrderIntegrator.html">FieldFirstOrderIntegrator</a>
+          interface). The following example shows how to implement the simple two-dimensional
problem using double primitives:
           <ul>
             <li>y'<sub>0</sub>(t) = &#x3c9; &#xD7; (c<sub>1</sub>
- y<sub>1</sub>(t))</li>
             <li>y'<sub>1</sub>(t) = &#x3c9; &#xD7; (y<sub>0</sub>(t)
- c<sub>0</sub>)</li>


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