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 <[email protected]> Authored: Wed Jan 6 13:20:25 2016 +0100 Committer: Luc Maisonobe <[email protected]> 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) = ω × (c<sub>1</sub> - y<sub>1</sub>(t))</li> <li>y'<sub>1</sub>(t) = ω × (y<sub>0</sub>(t) - c<sub>0</sub>)</li>
