[MATH-464] LegendreGaussIntegrator ignores defaultMaximalIterationCount and does 38 million iterations

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.1
• Fix Version/s: 3.0
• Assignee: Unassigned
• Reporter: Michael Borcherds
• Created: 31/Dec/10 07:00
• Updated: 24/Mar/12 16:16
• Resolved: 23/Aug/11 22:37

Description

The following code results in count = 37801710 which is effectively an infinite loop for typical functions we are using
(in GeoGebra)

The argument defaultMaximalIterationCount = 100 is being ignored

This is the version we are using:
http://www.geogebra.org/trac/browser/trunk/geogebra/org/apache/commons/math/analysis/integration/LegendreGaussIntegrator.java

LegendreGaussIntegrator gauss = new LegendreGaussIntegrator(5, 100);

try

{ double result = gauss.integrate(new testFun(), -10, 0.32462367623786328); }

catch (Exception ee)

{ ee.printStackTrace(); }

class testFun implements UnivariateRealFunction {

public double value(double x) throws FunctionEvaluationException

{ count ++; if (x>=0 && x<=5) return 0.2; else return 0; }

}