Author: luc
Date: Tue Mar 13 13:03:21 2007
New Revision: 517839

URL: http://svn.apache.org/viewvc?view=rev&rev=517839
Log:
added a section for the optimization package in the user guide

Added:
    jakarta/commons/proper/math/trunk/xdocs/userguide/optimization.xml   (with 
props)

Added: jakarta/commons/proper/math/trunk/xdocs/userguide/optimization.xml
URL: 
http://svn.apache.org/viewvc/jakarta/commons/proper/math/trunk/xdocs/userguide/optimization.xml?view=auto&rev=517839
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--- jakarta/commons/proper/math/trunk/xdocs/userguide/optimization.xml (added)
+++ jakarta/commons/proper/math/trunk/xdocs/userguide/optimization.xml Tue Mar 
13 13:03:21 2007
@@ -0,0 +1,88 @@
+<?xml version="1.0"?>
+
+<!--
+   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.
+  -->
+  
+<?xml-stylesheet type="text/xsl" href="./xdoc.xsl"?>
+<!-- $Revision: 480435 $ $Date: 2006-11-29 08:06:35 +0100 (mer., 29 nov. 2006) 
$ -->
+<document url="optimization.html">
+
+  <properties>
+    <title>The Commons Math User Guide - Optimization</title>
+  </properties>
+
+  <body>
+    <section name="13 Optimization">
+      <subsection name="13.1 Overview" href="overview">
+        <p>
+          The optimization package provides simplex-based direct search 
optimization algorithms.
+        </p>
+        <p>
+          The aim of this package is similar to the aim of the estimation 
package, but the
+          algorithms are entirely differents as:
+          <ul>
+            <li>
+              they do not need the partial derivatives of the measurements
+              with respect to the free parameters
+            </li>
+            <li>
+              they do not rely on residuals-based quadratic cost functions but
+              handle any cost functions, including non-continuous ones! 
+          </ul>
+        </p>
+      </subsection>
+      <subsection name="13.2 Direct Methods" href="direct">
+        <p>
+          Direct search methods only use cost function values, they don't
+          need derivatives and don't either try to compute approximation of
+          the derivatives. According to a 1996 paper by Margaret H. Wright
+          (<a href="http://cm.bell-labs.com/cm/cs/doc/96/4-02.ps.gz";>Direct
+          Search Methods: Once Scorned, Now Respectable</a>), they are used
+          when either the computation of the derivative is impossible (noisy
+          functions, unpredictable dicontinuities) or difficult (complexity,
+          computation cost). In the first cases, rather than an optimum, a
+          <em>not too bad</em> point is desired. In the latter cases, an
+          optimum is desired but cannot be reasonably found. In all cases
+          direct search methods can be useful.
+        </p>
+        <p>
+          Simplex-based direct search methods are based on comparison of
+          the cost function values at the vertices of a simplex (which is a
+          set of n+1 points in dimension n) that is updated by the algorithms
+          steps.
+        </p>
+        <p>
+          The instances can be built either in single-start or in
+          multi-start mode. Multi-start is a traditional way to try to avoid
+          beeing trapped in a local minimum and miss the global minimum of a
+          function. It can also be used to verify the convergence of an
+          algorithm. In multi-start mode, the <code>minimizes</code>method
+          returns the best minimum found after all starts, and the 
<code>etMinima</code>
+          method can be used to retrieve all minima from all starts (including 
the one
+          already provided by the <code>minimizes</code> method).
+        </p>
+        <p>
+          The package provides two solvers. The first one is the classical
+          <a 
href="../apidocs/org/apache/commons/math/optimization/NelderMead.html">
+          Nelder-Mead</a> method. The second one is Virginia Torczon's
+          <a 
href="../apidocs/org/apache/commons/math/optimization/MultiDirectional.html">
+          multi-directional</a> method.
+        </p>
+      </subsection>
+     </section>
+  </body>
+</document>

Propchange: jakarta/commons/proper/math/trunk/xdocs/userguide/optimization.xml
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