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From l..@apache.org
Subject svn commit: r1392414 - /commons/sandbox/nabla/trunk/src/site/xdoc/index.xml
Date Mon, 01 Oct 2012 16:01:16 GMT
Author: luc
Date: Mon Oct  1 16:01:16 2012
New Revision: 1392414

URL: http://svn.apache.org/viewvc?rev=1392414&view=rev
Log:
Fixed example code in documentation.

Modified:
    commons/sandbox/nabla/trunk/src/site/xdoc/index.xml

Modified: commons/sandbox/nabla/trunk/src/site/xdoc/index.xml
URL: http://svn.apache.org/viewvc/commons/sandbox/nabla/trunk/src/site/xdoc/index.xml?rev=1392414&r1=1392413&r2=1392414&view=diff
==============================================================================
--- commons/sandbox/nabla/trunk/src/site/xdoc/index.xml (original)
+++ commons/sandbox/nabla/trunk/src/site/xdoc/index.xml Mon Oct  1 16:01:16 2012
@@ -161,30 +161,38 @@
         </p>
 
         <p>
-          We can therefore find the maximal value by calling a solver on the
-          derivative. In this example, we will use
-          the <a href="http://commons.apache.org/math/apidocs/org/apache/commons/math3/analysis/solvers/BracketingNthOrderBrentSolver.html">
-          bracketings n<sup>th</sup> order Brent solver</a> from the <a
href="http://commons.apache.org/math/">Apache
-          Commons Math</a> library. Functions passed to any Apache Commons Math solvers
must implement a specific
+          We can therefore find the maximal value by calling a solver on the derivative.
+          As functions passed to any Apache Commons Math solvers must implement a specific
           interface: <a href="http://commons.apache.org/math/apidocs/org/apache/commons/math3/analysis/UnivariateFunction.html">
-          UnivariateFunction</a>. In order to comply with this
-          requirement, we wrap the derivative object into another
-          object adapting the interface and pass this wrapped
-          derivative to the solver:
+          UnivariateFunction</a>. In order to comply with this interface, we wrap the
+          derivative instance:
         </p>
 
         <source>
           UnivariateFunction wrappedDerivative = new UnivariateFunction() {
               public double value(double x) {
+                  // the VALUE of this new function is the DERIVATIVE of the original function
                   DerivativeStructure t = new DerivativeStructure(1, 1, 0, x);
-                  return derivative.f(t).getPartialDerivative(1);
+                  return derivative.value(t).getPartialDerivative(1);
               }
           };
-          UnivariateSolver solver = new .BracketingNthOrderBrentSolver(5);
-          double tMax = solver.solve(wrappedDerivative, 0.5, 1.5);
+        </source>
+
+        <p>
+          The final step is to call a solver on the derivative, as the roots of the
+          derivative are the local extremum of the original function. In this example,
+          we will use the <a
+          href="http://commons.apache.org/math/apidocs/org/apache/commons/math3/analysis/solvers/BracketingNthOrderBrentSolver.html">
+          bracketing n<sup>th</sup> order Brent solver</a> from the <a
href="http://commons.apache.org/math/">Apache
+          Commons Math</a> library:
+        </p>
+
+        <source>
+          UnivariateSolver solver = new BracketingNthOrderBrentSolver(1.0e-6, 5);
+          double tMax = solver.solve(100, wrappedDerivative, 0.5, 1.5);
           double yMax = derivative.value(new DerivativeStructure(1, 1, 0, tMax)).getValue();
           System.out.println("max value = " + yMax + ", at t = " + tMax +
-                             " (" + solver.getIterationCount() + " iterations)");
+                             " (" + solver.getEvaluations() + " evaluations)");
         </source>
 
         <p>
@@ -192,7 +200,7 @@
         </p>
 
         <source>
-          max value = 2.1097470218140537, at t = 0.8987751653383649 (7 iterations)
+          max value = 2.1097470218140533, at t = 0.8987751646846582 (11 evaluations)
         </source>
 
       </subsection>



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